Briefly fry the meat in a pan in olive oil, then remove. Braise the onion until clear in the same oil. Add the tomatoes, capers, basil and the fried meat, then salt. Cook on the lowest flame for about 1 hour, adding water during cooking if necessary.
Tip: the resulting sugo can be served as a starter with pasta, preferably orecchiette, traditionally with cacioricotta from Puglia grated over it (or alternatively parmesan). The cooked lamb and pork then make a wonderful main dish.