Food writer Julia Turshen believes in the power of leftovers. Now & Again, Turshen's latest cookbook, out Sept. 4 from Chronicle Books, teaches readers how to cook dinner tonight and how to reinvent any spare morsels as different dishes tomorrow.

"I've always loved leftovers," says Turshen, who intentionally cooks extra whenever she prepares food. "My wife and I eat almost every meal at home."

There's not much take-out in her Upstate New York town. Having some elements of a meal prepared in advance, like a hearty turkey meat sauce or a sturdy radicchio salad, means a meal is halfway made the next time you want to eat.

"Growing up, my family did not eat most meals at home, but my parents cooked on weekends," Turshen says. Her father's Sunday sandwiches, made from slices of Saturday's meat loaf, are among her favorite food memories. She thinks she may have inherited her reluctance to toss food from her mother, who stashed leftovers in the freezer because, though she hated to throw food away, she didn't know what to do with it. "She referred to it as her frozen garbage."

But Turshen most certainly knows what do with leftovers, and she spills all her strategies for using things up in Now & Again. "Really, it's a book about food waste without ever talking about food waste directly," she said. Learning how to manage your refrigerator is the mark of a skilled home cook. To that end, Turshen writes encouragingly about making substitutions to use up the groceries you have on hand no matter what a recipe says.

On Tuesday, Sept. 11, chef Valerie Erwin of EAT Cafe, Philadelphia's philanthropic pay-what-you-can restaurant, will cook a special dinner in celebration of Now & Again with recipes adapted from the book. Tickets include a copy of the book and cost between $55 and $95 (a portion of the pricier ticket level is a donation to EAT Cafe).

Guests can expect Erwin to put her own spin on some of Turshen's recipes, which, according to the author, is in the spirit of the book. "Valerie couldn't decide between the beef and zucchini meatballs and the lamb burgers, so she's making the meatballs with lamb," Turshen said. Other dishes on the menu will include charred broccoli with capers and lemon and yogurt cheesecake.

"What I look for in a guest chef at EAT Cafe is someone who shares our commitment to making the food system more inclusive and more equitable," Erwin said. Indeed, these values permeate Turshen's work. Her last book, Feed the Resistance, combines political activism and recipes, and a project close to Turshen's heart is Equity at the Table (EATT), a website she founded to promote "people of color and/or queer women/gender-nonconforming individuals who work in the food industry."

The EAT Cafe event won't be your only chance to catch Turshen and enjoy a meal from the book. She'll also be at Terrain Cafe in Glen Mills on Wednesday, Sept. 12, for a four-course dinner and book signing. Tickets cost $85.

Grilled Beef + Zucchini Meatballs with Tahini Dressing

Serves 6

2 zucchinis, ends trimmed, coarsely grated

5 garlic cloves, minced

1 small red onion, coarsely grated or finely chopped

1 egg, lightly beaten

1 tablespoon ground cumin

1 tablespoon nigella seeds (optional)

2 teaspoon ground coriander

Kosher salt

2 lbs. ground beef

3 tablespoons tahini

3 tablespoons fresh lemon juice

½ cup boiling water, or as needed

A small handful of chopped fresh herbs (cilantro, parsley, dill, and/or chives all work well)

  1.  Get your outdoor grill going (gas or charcoal) with high heat and make sure the grate is clean.

  2. Place the grated zucchini in the center of a kitchen towel and gather the towel around it to form a tight bundle. Wring out the zucchini over the sink, squeezing it as tightly as you can to release all of its excess water. Transfer the zucchini to a large bowl and add the garlic, onion, egg, cumin, nigella seeds (if using), coriander, and 1 tbsp. salt.

  3. Combine everything well, then add the beef and mix until well blended (your hands are the best tools for this job). Form the mixture into golf ball-size meatballs (it will make about 30 meatballs; make them whatever size you want, keeping in mind they will shrink a little as they cook). The mixture will be sticky, so wet your hands with a bit of water to help prevent the meat from clinging to them. Transfer the meatballs to a sheet pan in a single layer.

  4. If your grill needs it, brush the grate with a neutral oil (I like to fold up a paper towel and drizzle it with oil and then use tongs to rub it on the grate). If your grate has wide bars, you can put a wire baking rack, a mesh grill topper, or a sheet of aluminum foil on it so you don't lose any meatballs through the bars. Grill the meatballs, turning them a few times, until browned all over and just firm to the touch, about 10 minutes.

  5. Meanwhile, in a small bowl, whisk together the tahini, lemon juice, and boiling water. The mixture should run off your spoon. If it doesn't, add a splash more boiling water (the amount you need will depend on how thick your tahini is). Season the mixture  with salt to taste.

  6. When the meatballs are ready, transfer them to a serving platter and drizzle them with the tahini mixture. Sprinkle with the herbs and serve immediately.

Now & Again by Julia Turshen (Chronicle Books, 2018)