I second Bebero's basic sauce recipe...that's pretty much what I do. Now that it's getting hotter, I'll even just fry a little garlic and then chop up tomatoes (uncooked), basil and shelled, blanched broad (fava) beans and chuck that in with a drizzle of olive oil and some grated cheese. Another, even easier recipe is to fry garlic, add a jar of passata (smashed up tomatoes...get actual passata - the one in a glass jar with no added flavours or anything), basil and olives.
La juvenil does sauce, either in little tubs or you can ask for it. A lot of neighbourhood pasta shops will also do a basic "tuco" type sauce...Again, you often have to ask for it.