Gaia Bagnasacco serves homespun, absurdly affordable Italian salads, sandwiches, and pasta; bakes her own focaccia and pastries; and runs daily specials that belie the casual setting and $15-and-under price point. Be sure to heed the rules of the house: If you plan to visit after 4:30 p.m., pick up the phone and make a reservation; the 18 seats go fast and the kitchen closes at 6:30 p.m., except on Fridays and Saturdays when it burns the candle at both ends, and stays open until 7:30 and 9 p.m., respectively. BYO (Discovery Wines is around the corner, on B and 2nd). Order at the counter. And, for chrissakes, be patient: As Bagnasacco is fond of saying, “this is not fast food.” Also: “Gaia is based on food not on service.” You will want at least one baked pasta, cooked and served in a sort of tin pot you’d take on a camping trip, like the spinach-ricotta gnocchi barely bound by flour; and maybe a nice panino, like the Sano, with frittata, pesto, and Parmesan; and whatever special Bagnasacco has just scribbled on the board.