TO FIND Madison Park Conservatory, just set your GPS to “Best Restaurant Real Estate in Seattle.” You’ll find yourself at the tag end of Madison Street, the heart of the village known as Madison Park, at the two-level space overlooking Lake Washington that used to house Sostanza.

You’ll be there, but you still may not know it. Hanging where the sign should be is a wordless bronze pictograph of a goose in flight, its graceful silhouette enclosing a finely rendered skeleton. “That is some sign,” observed my guest. “Useless and disturbing.”

Cormac Mahoney, the owner and chef of Madison Park Conservatory, sees it differently. “The skeleton can be off-putting to people, but you’ve gotta be comfortable with it,” he offers. He’s referring figuratively to the structures underlying a restaurant—guests get a straight shot into the hot kitchen from the entryway—and literally to the fact that no guest of his should be timid about the insides of creatures. Asked what kind of food he’s doing at the conservatory, Mahoney will reply, “Delicious plants and animals with a squeeze of lemon.” Make that three or four squeezes of lemon—more on this later—and it’s not a bad tagline.

Inevitable, perhaps, from a chef who rejects culinary conformity. Schooled in the kitchens of preeminent rule-breakers Tom Douglas (Etta’s, Dahlia Bakery) and Matt Dillon (Sitka and Spruce), Mahoney learned to prize strict seasonality and creative ebullience over categorical precision.

Summer before last, during the ascendancy of the food truck phenomenon, he launched Tako Truk. It was a food stall on the sidewalk in front of the Eastlake Zoo Tavern—“a mobile food space with a Mexican name that wasn’t mobile or Mexican,” he grinned—where he’d slap coconut-braised pork belly with banh mi vegetables or bits of octopus with chorizo and yogurt into tacos, to be washed down with the lemongrass–kaffir lime infusion he dubbed Green Drink.

The result of this guerrilla pop-up was nothing less than a nightly culinary rave. Could he help it if regulars brought little airplane bottles of tequila to pour into Green Drink for street margaritas? And its three-month lifespan only burnished its legend. From there, a destination dinner house in the alligator-shirt-clad heart of establishment Seattle was hardly the next logical move. But the space, in a neighborhood that comes complete with captive audience, became available. And when his gastronomically simpatico friend and former Etta’s colleague Zoi Antonitsas announced she was returning from California, Mahoney decided to seize the moment. In November their Madison Park Conservatory opened its unsigned doors.

The food? “Delicious plants and ­animals with a squeeze of lemon.”

It’s classy inside. Lightly stuccoed walls, tiled floors, and North African lanterns whisper a global undertone; bundled willow branches aligned on the far wall lend sophistication. (The blue upstairs lounge is more intimate and full of sky and lake: beautiful for a nightcap.) For all the pedigree bound up in atmo and address, however—not to mention the thoroughbred name—Madison Park Conservatory isn’t forbidding: Baseball caps dined side by side with tuxes on one visit. Servers are plenty professional, yes, but once in a while the roguishly handsome Mahoney will trot out of the kitchen in cutoffs and a bandana to deliver a dish to a guest, and it’s Tako Truk redux.

So can the food be—in a more $25-ish sort of way. Similarly irreverent collisions of cuisine and bright flavor happen here, as when slices of grilled walnut bread spread with luscious foie gras came dotted with pickled gigante beans and tart kumquats; or when unctuous hunks of duck leg confit arrived as a satisfyingly rustic ragout with cauliflower, cashews, and apricots; or when Alaskan spot prawns conspired with warm Savoy spinach, chunks of feta cheese, and candy-sweet crescents of delicata squash to produce genuine magic on the palate.

The prawns were mealy, alas. Indeed, we found Mahoney’s perfect pitch for complementary flavors and textures to be occasionally marred by amateur errors—unnuanced hits of chocolate in the gremolata of an otherwise fine crisped pork belly dish, too heavy a hand with the lemon in a baby lettuce salad, a main dish of fire-roasted shellfish over chickpeas that lacked the heft of main-dish status. One dessert, gummy apple bread pudding, was actively awful.

And all the rest of the desserts—particularly the savory ones, from olive oil ice cream to rods of dense, delectable pine nut biscotti—were magnificent. Make of this what you will. It tells me Mahoney’s got chops—amply evident in the glorious simplicity of a whole trout, served stark across a white plate with pine nuts, currants, and capers; or his heavy-light touch with a generous dish of crab tajarin pasta; even in his way with chicken, so often the house throwaway, but lavished here with careful roasting, moist prunes, and a tangy watercress bread salad.

Without question, this chef and his team have the stuff to dazzle at the unofficial commissary of Madison Park. The question is whether they have the discipline to do it consistently.