When diners come to Zahav tonight for another busy edition of Restaurant Week, it's a fair bet many, if not most, will be ordering the haloumi.

This salty and firm sheep's milk cheese - pan-crisped to a toasty brown on the outside but still warm and irresistibly oozy in the middle - comes with sweet dates, sumac-pickled onions, walnuts, and an earthy dusting of Urfa chile. And it has understandably become one of Zahav's untouchable menu stars.

"If we try to take it off, people freak out," says Zahav chef and co-owner Michael Solomonov, who serves up to 75 orders a night. "If we change it at all, people revolt."

But something important has most definitely changed this week: the haloumi itself. Instead of coming from Cyprus, the island that claims haloumi as its pride and has long been its sole producer, this version will be coming from New Jersey's Valley Shepherd Creamery, which has a stand in the Reading Terminal Market.

"It's so damn good," says Solomonov. "You can taste the nuance of the cheese, the grass, the milk. Anytime we improve the quality of ingredients we're using, it adds to the restaurant experience."

How Zahav and Valley Shepherd came to this collaborative haloumi moment, however, is a fascinating tale of how local foods can be shaped by an unlikely series of much wider forces than grass and milk, from volatile economic crises overseas to the growth of American craft cheesemaking and a sudden realignment of the largest flock of sheep in the United States.

Solomonov's concerns about his haloumi supply first arose two years ago during the Cypriot financial crisis that presaged the Greek troubles roiling this summer's headlines.

"We were scared because prices were going up, and we already spend $1,000 on haloumi a week," he said. "And then cases starting coming in frozen. When you thaw frozen haloumi and put it in a pan, it's not pretty. It gets watery and breaks apart. But the thing is: There's no other haloumi. It all comes from Cyprus."

As most haloumi gets imported alongside Greek products, serious concerns spiked again in early July, when Greek voters rejected the initial European bailout offer, sending up red flags with major importers like Titan Foods, which feared supply interruptions. Since the Greek reversal in which new austerity measures were implemented, "we're no longer worried," said Titan's controller, Anthony Fidakis. "But, obviously, the markets have changed."

In the meanwhile, Valley Shepherd owner Eran Wajswol suddenly came into 800 new sheep this year due to the sale (and downsizing) of New York's Old Chatham Sheepherding Co., previously the largest sheep dairy in the country.

"I didn't have enough milk before," says Wajswol, who had struggled to meet his company's continual growth due to the peculiarities of sheep, which provide milk only between spring and fall. "Sheep make amazing milk, but they are horrible milkers."

With a three- to four-month maturing period required for the cave-aged raw-milk cheeses that are Valley Shepherd's specialty, however, there has always been a gap each summer when the previous year's cheese supply ran dry. Until now. By more than doubling his flock, Wajswol has closed the gap, and then some, producing enough milk to finally begin producing fresh cheeses that require no aging at all, like the haloumi and a new, exceptionally creamy feta. Both products blend in 30 percent goat's milk.

For the iconoclastic Wajswol, who views cave-aging as the cheesemaker's noble art, dabbling in "silly little" fresh products has been a reluctant step. Then again, crafting a haloumi to meet the standards of a chef like Solomonov has not been easy, either.

Haloumi dates to the medieval Byzantine period and is popular throughout the Middle East, where its preservation in brine was prized in the days before refrigeration. Its curious ability to be panfried or grilled crisp without melting away is due to its lack of acidity, says Wajswol.

Nailing the right texture - firm, but not too firm - has been arduous, Solomonov rejecting batch after batch as not creamy enough. Wajswol adjusted cooking times, lowered temperatures during the shaping phase, lessened the intensity of pressing, then homed in on the ideal shape for the bricks, which are dropped into a vat of hot whey, where they are poached and "seared like a steak."

After the most recent batch, Solomonov sent his verdict by text: "Better."

"Better?!" replied Wajswol. "That's about as good as you can get from him."

"Good enough," Solomonov added, ready to place his first 30-pound order.

"Thank God!" said Wajswol.

He has found an even tougher customer, though, in Konstantinos Pitsillides, the famously opinionated Cypriot chef who will move his Kanella to a larger Front Street space this month.

"The feta was really good - creamy but still crumbly. But I'm skeptical about the haloumi," says Pitsillides, who pan-roasts haloumi as saganaki with fig salad, but who also grates the cheese to stuff everything from minted ravioli to meats. "Good texture . . . but more or less tasteless. It should have more fat content, more salt, and mint. I gave [Wajswol] some suggestions."

For the record, I disagree with Pitsillides, finding it subtly sweet with an irresistible sheepy twang. But as a native of haloumi's homeland, his opinion must be considered.

Pitsillides was especially emphatic that Valley Shepherd not call its cheese "haloumi," a name protected by the European Union: "It's Cyprus' national treasure. We don't have a lot to brag on, but haloumi is one of them."

Wajswol says the cheese is still technically "in development" but promises a proper name, which "requires substantial consumption of adult beverages at our next farm party."

In the meantime, local chefs are already having fun with the new ingredient, whose salty profile and contrasting textures require accompaniments that "go big with sweet, sour, or spicy," says Solomonov. "I don't do neutral things with haloumi."

At Helm, co-chefs Kevin D'Egidio and Michael Griffiths have gotten that message with their approach, serving plancha-seared haloumi with sweet and sour plums and a plum sauce touched with holy basil. At Zahav, Solomonov has been experimenting with a new addition roasted over coals and paired with a summery peach sauce blended with tangy "amba" mango pickle and served with raw corn and pecans.

"[Valley Shepherd's haloumi] is more expensive," he says. "But it's better than the store-bought product. You can taste the grass the animals were eating. It tastes like actual cheese. And I know where it came from."

Of course, being so fresh, it is more delicate, with a shorter window in which the center remains molten, meaning less wiggle room for the kitchen.

"My sous chef is pissed at me right now," he said. "But the moment I took a bite of this last batch she knew this was going to happen. And we'll be a better restaurant for it."

Zahav's Haloumi with Dates, Walnuts and Sumac Onions

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Makes four servings

1/2 cup toasted walnuts, chopped

1 cup dried dates, roughly chopped

1 tablespoon sherry vinegar

1/3 cup olive oil

Salt

1 tablespoon canola oil

8 ounces haloumi cheese, cut into 1-inch cubes

1 cup "sumac onions" (see recipe)

Parsley, chopped

1/2 teaspoon ground Urfa peppers

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1. For the date paste, combine the walnuts, dates, sherry vinegar, olive oil, a couple of pinches of salt, and ½ cup hot water in a food processor. Puree until smooth and set aside.

2. Film a skillet with canola oil and place over medium-high heat until the oil is shimmering but not smoking. Put the cheese cubes in a single layer in the skillet and cook, turning, until the exterior is golden and crisp; about 2 minutes per side.

3. Spread the date paste over the bottom of a serving plate, add the fried haloumi, and top with the sumac onions, Urfa, and parsley. Serve immediately.

Note: To make sumac onions, combine one thinly sliced red onion, one tablespoon red wine vinegar, one teaspoon ground sumac, and a half-teaspoon of kosher salt in a bowl and toss.

Per serving: 636 calories; 22 grams protein; 39 grams carbohydrates; 31 grams sugar; 46 grams fat; 60 milligrams cholesterol; 564 milligrams sodium; 5 grams dietary fiber.EndText

Peach Amba

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Makes four servings

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8 ounces Valley Shepherd haloumi cheese, cut into 11/2-inch cubes

2 peaches peeled and pitted

1 tablespoon kosher salt

2 teaspoon of granulated sugar

2 tablespoons of Amba (otherwise known as mango pickle), available at Middle Eastern grocery stores

2 tablespoons picked cilantro leaves

1 peach, washed, pitted, and sliced thin

1/2 cup of raw corn kernels (sweet and in season)

1/4 cup pecans, lightly toasted, salted, and roughly crushed

Finishing salt, such as Maldon or Cyprus Black

4 metal or bamboo skewers soaked for 12 hours

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1. The night before you intend to serve, toss the peaches with the salt and sugar and leave uncovered in the fridge.

2. The next day, in a covered small sauce pot on low heat, stew the peaches for about an hour or until super soft but not caramelized.

3. Remove from pan and allow to cool at room temperature for an hour.

4. Place peaches and Amba in a blender and puree until smooth, adding salt, if desired. Reserve.

5. Fire up your grill with charcoal, preferably, or gas if you are a chump.

6. Load the haloumi on the four skewers carefully and place over coals or directly on a well-oiled grill rack.

7. Cook on both sides for around 3 minutes each, or until the exterior is brown and the interior is soft.

8. Spoon the sauce onto four bowls or plates. Place skewers on top. Garnish with peach slices, corn, pecans, cilantro leaves, and finishing salt, if desired.

Per serving: 359 calories; 20 grams protein; 15 grams carbohydrates; 11 grams sugar; 25 grams fat; 60 milligrams cholesterol; 1,976 milligrams sodium; 2 grams dietary fiber.EndText

Ravioli Stuffed with Haloumi and Mint in Yogurt Sauce

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Makes six-eight servings

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For the dough:

1 pound of type 00 flour

4 tablespoons sunflower or corn oil

1 teaspoon of salt

1 cup of warm water

For the filling:

1 pound of coarsely grated haloumi

4 tablespoons of crushed dry mint

1 tablespoon of freshly ground black pepper

1 large egg lightly beaten

For the sauce:

Vegetable stock (make your own or simply use vegetable paste)

Half a bunch of fresh mint

1 cup of Greek yogurt

100 milliliters of heavy cream (just under 1/2 cup)

Semolina flour for dusting

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1. Combine flour, oil, and salt in an electric mixer fitted with a hook. Beat mixture for 1 minute. Pour in water and beat until the mixture is smooth and well combined (if needed, add 1 to 2 tbsps of water).

2. Sprinkle flour on a work surface, knead dough by hand until it is smooth and elastic and does not stick on hands. Form dough into a ball and wrap tightly with plastic. Let it rest for a half-hour at room temperature.

3. Meanwhile, prepare the filling by combining haloumi, dry mint, pepper, and egg.

4. Cut the ball of dough into four pieces, reserve the dough you're not immediately using, and cover to prevent it from drying out.

5. Dust the counter and dough with flour and roll dough through pasta machine until it becomes a paper-thin sheet. Using a cup, small bowl, or other tool, cut 3-inch rounds out of your dough.

6. Drop 1 tablespoon of filling onto each round of pasta. With a brush or your finger, brush a little water on the perimeter of the dough, then fold the unfilled half over the filling and gently press with fingers to form a seal.

7. Dust a tray with semolina flour and place ravioli on it. Continue preparing the remaining ravioli. If making ravioli in advance, dust with semolina to prevent them from sticking and keep uncovered in the fridge.

8. Before serving, heat the vegetable stock and bring to a parboil stage. Add ravioli and cook for 8 to 10 minutes.

9. Meanwhile, in a wide, large, shallow saucepan, add cream and 1 cup of the vegetable stock, and bring it to a boil. Add yogurt and whisk until yogurt dissolves. Turn off the heat.

10. Immediately add to sauce the drained ravioli and fresh whole mint leaves. Put ravioli on large plate or plates. Garnish with grated haloumi.

Per serving (based on 8): 619 calories; 27 grams protein; 50 grams carbohydrates; 4 grams sugar; 34 grams fat; 102 milligrams cholesterol; 667 milligrams sodium; 2 grams dietary fiber.EndText

Reading Terminal Market, 267-639-3309; valleyshepherd.com

claban@phillynews.com

215-854-2682

@CraigLaBan

www.philly.com/craiglaban