Preheat oven to 350�F.
Wash the tomatoes and slice them in half, horizontally. Place them in an oiled medium/large baking dish with the sliced side up and bake for 1/2 an hour.
Remove from the oven and put a slice of mozzarella on each tomato half along with a drop of olive oil, a sprinkle of oregano and some bread crumbs.
Return to the oven for 5 minutes. These can be served hot or at room temperature.