My mother once set out to perfect her quiche. If she were to try again now, I would send her straight to Mercat, where each slice is a perfect tower of wobbly custard. I come here for a hit of Parisian bistro. The kitchen turns out crisp frites and an extraordinary beurre blanc. Asparagus mimosa has a showering of finely grated egg and creamy vinaigrette over crossed, vibrant spears. Steak tartare is satin, and onion soup has a shimmering, rust-colored broth. The decor is part of the charm. Marble tabletops, curve-backed wooden chairs, and sweet vintage china accent an intimate space where menu items are written on mirrors over the bar and much is, in a word, delightful. I find more versatility and playfulness at lunch, where the menu features standards (you can get a jambon beurre—just ham, butter, baguette) without the pitfalls of dinner. Veal sweetbreads were small, wrinkled stubs over chicory soppy from a poached egg and bacon vinaigrette, and we had to hunt for the leeks under Chilean sea bass that had languished on the pass. Service can be languorous. Then again, people linger, sipping coffee or the last of their wine. Or, in the case of three gentlemen near me, second rounds of the French 76 with St. Germain, Hennessy, Prosecco, and lemon. There’s a word for them in France: connoisseurs.