"Welcome to Heirloom," our waitress said, her friendly but very deliberate tone barely audible through the din that pulsed through this lively new Chestnut Hill new restaurant. "We are a 'fine American cookery.' "

Did she really say that? Not since a visit to Colonial Williamsburg, methinks, have I heard a server describe a restaurant as a "cookery" with a straight face. But Heirloom — despite a stiff demeanor that can sometimes give this BYOB an overeager awkwardness — is very serious about its mission to highlight regional American and seasonal flavors, from the buttery fresh-baked pocket buns in the enticing bread basket to the seafood "purloo" inspired (however loosely) by coastal Carolina.

And Chestnut Hill, long-suffering in its wait for some quality fine dining, but now on somewhat of a roll with last year's Mica, has responded to this latest addition with gusto, pouring into the 44 seats of its votive-lit, glass-walled space in the Top of the Hill strip mall, even sitting alongside strangers around the long wood community table that runs down the center of the cinnamon-colored room.

Heirloom isn't perfect, especially for a place with entrees in the mid-20s. But the ingredients are genuinely good, and there is an earnest warmth to dining here that compensates for the occasionally goofy manner and busy dishes. Chef Al Paris' unbridled ebullience, expressed these days in cornucopias of fiddlehead ferns, baby favas, and almost-shucked peas playing peekaboo from their half-opened pods, is bursting across the plates.

He's got reason to be happy. Paris, 54, who has cooked a phone book of different concepts in the last 15 years to varying degrees of success, from French bistro (Oberon) to Asian fusion (Guru, Mantra), to old-school meatballs (Pat Bombino's) and neo-soul food (Zanzibar Blue), is creating some of the most appealing and relevant menus of his career.

Turning to muses as diverse as the midcentury cookbooks of Ruth Berolzheimer (for spoon bread) and local forager David Siller (for stinging nettles and ramps), Paris is clearly having fun melding snippets of Americana with in-the-moment inspirations. Tender "preserved duck leg" (also known as duck confit) comes alongside a custard of Jerusalem artichoke. Rich split-pea soup is soulful with the rustic tang of Benton's bacon and the pulled leg meat of chickens smoked over applewood out back. A classic crab cake, sweet with fresh lump, is served on a simple-but-satisfying sauce of tomatoey shrimp gumbo. Pan-seared halibut with fennel-infused saffron stew comes over a green swoosh of chickpea puree, beneath a melting pat of Pernod butter.

Paris admits he isn't always as true to the ideal of local-seasonal ingredients as he'd like. What is a tomato-mozzarella salad doing on this menu in early April — at a place called Heirloom, a term whose food meaning found its first real mojo with forgotten tomato specimens like the "Green Zebras," "Brandywines," "Cherokee Purples," and "Aunt Ruby's German Greens"? That Paris is now running a contest, soliciting pre-1950 recipes for possible inclusion on his early-summer menu, proves his heart is in the right place.

"I know, I know," he concedes, "but the folks up here expect a tomato salad when they walk in. I was pandering."

At least he was cooking, too, smartly roasting those spring tomatoes in the pan to enhance their tenderness, and pairing them with a milky cloud of cream-stuffed burrata cheese. Likewise, I loved the appetizer of French snails simply tossed with hand-cranked noodles, zucchini laces, and a hit of Fresno pepper to warm the butter-garlic sauce. The wonderfully refreshing Carolina chop salad, molded into a pedestal of crunchy romaine studded with crab, shrimp, and the campfire tang of smoked tomato vinaigrette, has the look of a Chestnut Hill classic. The fresh-fried doughnuts whose holes are stuffed with apple-pie filling could become a draw in themselves as well.

There were moments when Paris could have used an editor to delete the superfluous ingredients from some plates. Two excellent medallions of Broken Arrow Ranch venison caught my attention with pureed parsnip and huckleberry-kissed demiglace — but skidded out of control with the overly sweet carrot custard on one side, and a chestnut-flour crepe stuffed with jarringly ripe Camembert on the other. I also would have loved the "purloo" unconditionally, its rice soaked in spicy tasso cream and jeweled with sweet scallop, shrimp, and perfectly poached oysters. But he should have stopped before plunking a glob of cheap neon-red and black fish roe on top.

His loose take on "pepper pot" was also intriguing, focused on a soft hunk of slow-braised short rib. But the dish was so sweet, both from too many bell peppers and the odd addition of currant jelly, that it strayed too far from the old-school source. The melt-away gnocchi Parisienne in the dish, however, were memorable, lending at least one redeeming element to the plate — a trend that seemed to persistently buoy Heirloom's weaker dishes.

The equally old-school "mushroom loaf," a sort of veggie scrapple, was overspiced to compensate for its stick-to-your-ribs density, but also leavened by sweet pumpkin tortellini and adorably bitter baby turnips. The big pork loin with maple-pecan glaze was a bit bland, but I loved the zing of gingersnaps in the gravy, and the creamy spoon bread that was almost worth the dish itself. Fresh and snappy fiddleheads, minced stinging nettles, and a beautifully brick-colored Arctic char more or less compensated for the shame of cooking precious white asparagus to fibrous mush. Some overcooked Asian eggplants were an afterthought once I forked into the cuminy fava-bean pancake that framed a gorgeous rack of lamb from nearby Erdenheim Farms in Lafayette Hill.

Their woolly flock of Cheviot sheep descend (however indirectly) from a 14th-century Scottish breed. As long as these rosemaried savory racks are roasted to a perfect medium-rare, and Al Paris keeps cooking like a contented comeback chef, that's more than "heirloom" enough for me.

Contact Craig LaBan at 215-854-2682 or claban@phillynews.com, or follow on Twitter @CraigLaBan.