Why is it so many restaurants do starter courses better than entrees?

I have theories, of course. Smaller plates are freighted with less-expensive risk, so chefs feel freer to take chances. Smaller plates provide the innate challenge of brevity, forcing cooks to focus their sharpest ideas. Inside the constraints of an appetizer or primi pasta, a masterful technique or seasonal whim can be the star, instead of supporting cast to a $28 hunk of prime meat or fish.

Russet is one of those fast-from-the-gate players. And the opening dishes are so fine, I can taste in the exquisite pastas, charcuterie, and vivid foraged flavors both the restaurant's considerable potential, and the distinguished lineage of the chef's training.

Zipper-edged stradette pasta flecked with the earthy sweetness of cornmeal twirl beneath a ragu of duck and the surprising sweet-tart pop of tiny fraises de bois strawberries. Housemade lonza, chile-cured from the loin of Tamworth pigs Russet buys whole from Lancaster County, comes sliced into a translucent amber rosette draped with pickled ramps, blanched celery leaves, and a rustic green oil with mortar-crushed herbs. Stinging nettles, plucked for the restaurant by urban forager David Siller, are spun into silky strands of forest green tagliolini, glazed with the capery anchovy piquance of bagna cauda, and then set beneath a lightly broiled yolk that bursts into sauce at first touch.

Chef Andrew Wood, 36, and pastry chef Kristin Wood, 38, are the co-owners of Russet. And they've returned to Andrew's home region to open this simple but elegant BYOB in the former Ernesto's after working a tour of the country's best restaurants. They'd journeyed from Radius (in Boston), where the couple met, to Trio and Tru (in Chicago), to Quince in San Francisco, and then back to Philadelphia, where they helped open James. Andrew then worked as butcher at the short-lived Maia before landing as sous chef at Fork.

The Italian influences of Andrew's time with Michael Tusk at Quince are obvious here. So is the Northern California reflex for seasonal ingredients and sustainability, from the recycled fabrics they used to upholster the chairs and banquettes (all 52 seats) to the antique sconces that warm the sparely painted cream and burgundy room, to the relationships they've fast secured with local farmers.

Of course, the farm-to-table movement has become common. But few restaurants live the notion quite as thoroughly as Russet, where Wood has the know-how and resourcefulness to buy animals whole, whether it's one of the 10-pound drakes he stews for a day into duck ragu; the steer from Green Meadow Farm that gave him 1,000 pounds of meat to brine, braise, age, grind, or roll into involtinis; or the five heritage pigs he has contracted this year to turn into prosciutto (currently hanging downstairs) or mince into a chile-flared ragu (shoulder, ears, snout) over pici noodles extruded through a bronze die like spaetzle.

Even the big halibuts Wood orders directly over the phone from a captain in Alaska are put to multiple use. The fillets are steamed to perfection in parchment over a bed of spinach, tarragon, and asparagus. The bones, meanwhile, are steeped into the foundation of a bouillabaisse turned black with cuttlefish ink, then tossed with orecchiette for one of the more stunning pastas, whose earthy, almost truffle-y sea-flavored gravy is offset by pristine ivory scallops and the sweet tang of slow-cooked Jersey tomato fondue.

The freedom of such a free-flowing menu, though, has its drawbacks. With only a handful of selections based on market availability, the room for error is slim. And our dinners hit some unexpected bumps in entree mode.

The actual ingredients were less of an issue than redundancy. At one meal, all four dishes came anchored with greens. They made an aromatic cushion for the halibut, and a pleasantly bitter contrast to the exceptional roast chicken, with turnip greens and baby turnips. But by the time I munched through the kohlrabi greens and salty ham shards beneath my severely undercooked salmon (basically, a brick of raw fish), the stemmy pile of foraged garlic mustard greens with the pork Milanese was so spicy, it overshadowed the other issue of the pork's lack of tenderness. At my next meal, after another impressive round of starters highlighted by several pastas and a creamy sformato flan infused with toasted garlic, the focus of our entrees was good — a meaty chunk of golden tilefish, tender duck breast with rhubarb mostarda, and a gorgeous Lancaster leg of lamb. The lamb was a solid success. But detail flaws took away from other dishes. Bitter chunks of pom-pom mushrooms that for some reason tasted like clay should never have been sent with the duck. A sheer wrapper of lardo enveloped my tilefish in a see-through parcel of pig fat that, visually and texturally, was a disconcerting distraction from the pristine fish and pretty cilantro flowers laid on top.

In a restaurant whose appeal is all about earnest flavors and great ingredients, something like an off garnish can matter — and show Russet still has lots of room to grow.

If that does happen, Kristin's pastries will be keeping pace, and her desserts are as seasonally driven as the menu. Lemon verbena-infused buttermilk panna cotta come with orange-apricot marmalade; classic brown butter tart is topped with a pinwheel of rhubarb and honeyed meringue; ice cream is vivid with the depth of sweet-sour of wild plums.

There was also an exceptional ice cream with Ommegang's Art of Darkness, a malty ale that tasted like boozy dulce de leche. Topped with a crunchy sesame tuile, it was good enough to make me think the end of my meal was as good as the beginning. Once Russet tidies up all those stray greens and odd garnishes cluttering the middle, we'll have a complete restaurant to compete with our best.

Contact Craig LaBan at claban@phillynews.com.