On a quiet Trastevere backstreet, La Botticella offers pure Roman cooking, outside under the lines of flapping washing or inside in the picture-lined salon. Menu stalwarts include tripe and rigatoni alla paiata (pasta with calf’s intestines), but there are less demanding dishes, such as an excellent spaghetti all’amatriciana (Roman pasta with a spicy tomato sauce, pecorino and guanciale, or baconlike pigs’ cheeks).