Sometimes the finesse of fine chefs makes us forget that fusing disparate flavors in a single dish requires considerable art and skill. A new Upper East Side French/Asian spot serves as a reminder that it’s not always as easy as experts make it seem. Launched in late summer under the eye of Renaud LeRasle, who worked for P. Diddy as well as at the lamented Russian Tea Room, Rêve is now in the hands of accomplished executive chef Christina Kelly, but it seems slightly adrift.

A meal at the small, one-room corner restaurant gets off to an uncomfortable start. The brick-lined room’s awkward, tight arrangement maximizes overheard conversations and inter-table collisions while requiring some deft maneuvering on the part of the waitstaff — who nonetheless remain delightfully friendly, efficient, and sweet throughout.

After you’ve been seated, a heaping basket of cranberry-nut bread arrives at the table with a dish of pale gold room-temperature butter. You spread a little and taste — is the butter rancid? No: it’s been mixed with pungent, bitter sesame oil to make your first bite at the restaurant a startling one. Fortunately the bread is excellent on its own, but a tone of faint mistrust has been set for the meal.

The menu proves as hard to navigate as the room: Among a deluge of ingredients, entries like truffled nage edamame or sweetbreads with lime ponzu conjure no familiar mental images. The cooking walks an uneasy line, neither wildly experimental nor simply satisfying. Any given dish is unpredictable; instead of drawing out and complementing the flavor of good ingredients, Ms. Kelly just brings together several diverse flavors with an often hard-to-detect logic. Sometimes fortune smiles on a dish and its elements mesh, but too frequently disharmony reigns.

A starter of fried calamari ($9) approximates the bar-food classic: the crisp flour-dredged squid strips are succulent and salty, with just a hint too much resilience in their texture.Instead of complementing their fried mildness with a bit of tang, though, the kitchen lays the calamari in a vivid green pool of syrupy, semi-sweet sauce thick with the dark, mouth-filling flavors of wakame seaweed and sesame. Asian-style duck dumplings ($12) have thick, doughy, crisp-fried wrappers filled with substantial chunks of tasty duck meat, served with fresh corn and sliced mushrooms and a tart soy sauce; by keeping its ambitions within reason, the dish succeeds better than most. A Thai-inspired bowl of mussels ($9) does even better: Creamy baby bivalves develop nicely in a light red-curry coconut broth with basil sprouts and no extraneous complications. But a large, bready crab cake ($12) is confused and overwhelmed by a tomato sauce that’s too bright with complex South Asian spices and an excessive, cloying potato puree.

Simplicity is similarly hard to find among the main courses. A pan-roasted snapper filet ($24) has a substantial, savory crust and excellently lean and firm flesh that cries out for a clean, flavorful foil but receives the opposite; one must consult the menu to discover that the tart, disconnected accompaniment on the plate is “potato basil sauce, kimchi vegetables, and tamarind jus.” Though the fish’s quality is good, ahi tuna ($24) suffers again from a high concept-to-execution ratio; tuna meat is wrapped in seaweed, battered, fried, sliced, and dotted with wasabi cream, a harsh treatment that fails to bring out the best in its mild flavor. The accompanying tartare of the same tuna falls along standard lines: it retains the flavor and supple firmness of the flesh but inundates it in a thin, sour guacamole.

Soft, almost mushy rosemary gnocchi ($14) maintain a respectable degree of woodsy harmony: rich chestnuts,a creamy,herby sauce,and a forest of chewy enoki mushrooms meld with unexpected success. More dishes like this would be quite welcome here. A plate of short ribs of beef ($21) also shows the expertise the kitchen can wield when it doesn’t overreach or overthink. The pile of tender,substantial meat in a dark,rich wine reduction needs no improvement; mercifully, the dish’s gratuitous Asian element, a smattering of toasted black rice throughout, neither adds nor detracts from the whole.

Rêve’s small, unpretentious wine selection takes a scattershot approach to pleasing a crowd. Beringer’s nuanceless white zinfandel ($30) is proudly featured alongside a beautiful young Jean Boillot Puligny Montrachet ($90). A host of familiar American and French bottles rounds out the list. Among the by-the-glass offerings, Brancott’s fresh and full New Zealand sauvignon blanc ($8) stands out, as does a smoke-tinged La Ferme de Gicon Côtes du Rhône ($7).

The restaurant’s fruity desserts achieve what the rest of the menu does not: simple pleasure.A fluffy, moist pumpkin baba rum ($9) is untraditional but subtle and delicious; a quince tart ($9) showcases the fruit without unnecessary complication. Filipino-style banana spring rolls ($8) manage an excellent balance between lightness and richness, with abundant caramelized banana flavor.

Rêve gets a lot right — all the ingredients are fresh and good, and the execution of dishes is skillful across the board. But the incommodious dining room doesn’t encourage return visits, and the restaurant’s creative tiller seems unsteady, producing jarring, chaotic anti-comfort food that fails more often than it succeeds.

Rêve, 1347 Second Ave., 212-288-5285.