Rinse the tomatoes well with cold water. I normally cut them in half, and also cut off any stems or blemishes, then add them to a bowl. Roughly chop the olives and add to the tomatoes.
Squish the mixture with your fingers so the tomatoes give off some juice and everything is nicely mixed.
Drizzle in a very little bit of the vinegar and olive oil.
Stash this in the fridge for a while if you have time, then top with some shredded basil just before eating.
Another great way to serve this is to toast some slices of cheese bread (try my recipe #138924), rub both sides with a cut garlic clove, then mound the tomato mixture on top. Lay very thin slices of the fresh mozarella on top, and broil for a minute or two. Garnish with shredded basil and freshly ground black pepper.