Trecca, in Ostiense, is the trattoria of the Trecastelli brothers, with a menu that follows the market and changes almost every day. The dining room has the feel of a neighborhood bistro: a white-and-terracotta checkerboard floor, marble tables, bottles scattered here and there on shelves, and an open kitchen beyond the counter. The marinated eggplant gets the meal off to a flavorful start. The bucatini all’amatriciana is thoroughly convincing: perfectly al dente, with a well-executed sauce and guanciale crisped just right. It is followed by rigatoni with oxtail ragù alla vaccinara and well-seared lamb chops, then the house tiramisù. The service is courteous.