Vaux began life a year ago as a fancier restaurant, and the decor shows it. The well-spaced tables are linen-napped, the banquettes plushly upholstered, and the color scheme a medley of lulling beiges. It’s a room your great-aunt could appreciate. But this sedate establishment—with a menu tending toward foie gras and lobster, and entrées nearing $30—found itself planted in fallow soil on the wrong Fifth Avenue: Brooklyn’s.

So the place was retooled as Vaux Bistro. And luckily, the owners didn’t look to the East Village for inspiration. What Avenue B bistro could manage “asparagus flan in a light parmesan cream” ($7), a shimmering puck of green loaminess with all the vegetable’s flavor and none of its fibrosity, flowed with a light, off-white sauce whispering cheese? Three stalks of firm asparagus form a triangular frame, reminding us how much effort went into the transformation. Other appetizers retain this rare combination of simplicity and elegance, including a score of mussels ($6) yanked from their shells, lightly crumbed and fried, and scattered around a rémoulade sharpened with bits of vinegary cornichon.

Though the food flaunts all sorts of French flourishes, there is an elemental and abundant quality about it that I associate with the best American cooking. And a trudge through the Slope’s unplowed streets one snowy evening demonstrated how welcome this quality can be. Sided by mashed potatoes, the pork loin ($15) sprawled on a huge plate, three outsize cylinders seared on one side and faintly pink in the middle. The loin came coated with a sauce composed of plain apple cider and Calvados—an inspired union of youth and age that didn’t upstage the pork. This philosophy of sidelining sauces to a light and flavorful trickle succeeded elsewhere as well, including a sliced duck breast with a wonderful watercress emulsion tasting like a new-mown lawn, and a crisp-skinned salmon filet ($15) soaked in anchovy butter, reviving a fish grown weary in the service of midpriced restaurants.

But my delight with the sauces was not to last. When I returned a month later, the watercress emulsion had been replaced by an inferior pomegranate concoction. A few weeks after that, a bitter-orange drizzle had banished the apple juice from the pork loin. And, greatest tragedy of all, the asparagus flan bathed in liquid parmesan had vanished entirely, in favor of a timid garlic flan doused with what tasted like strawberry pancake syrup from IHOP (though the menu claimed it was carrot broth with candied fennel). There were still plenty of good things on the menu—the salmon, the fried mussels, the seafood sausage. But I missed those sauces, and felt like a fundamental bistro tenet had been violated: the principle that you could return again and again to enjoy a favorite dish.

Englishman Calvert Vaux (pronounced “vawks”), the lesser-sung partner of Frederick Law Olmsted, codesigned Brooklyn’s Prospect, Fort Greene, and Tompkins parks, as well as Eastern and Ocean parkways. Revisionist architectural historians suggest his contributions may have dominated. Vaux also redefined the American house through his book of patterns, Villas and Cottages (1857), and, later in life, engineered the city’s first low-cost housing. Like the sauces, Vaux vanished mysteriously one evening. He was found floating facedown in Gravesend Bay the next morning.