Dip the capers in water and leave the salt to loosen for an hour, then drain them.
Finely chop the garlic and put it to fry in a pan with the oil and the anchovy.
Let cook till the anchovy is thoroughly melted.
When done, add the tomatoes, the capers, the oregano and let simmer, stirring now and then, on a medium heat for five-six minutes, until the sauce is thick.
Season to taste with salt and pepper and add the basil leaves then turn the burner off.
Meanwhile, broil the steaks seasoning them with salt only when done.
Add them to the sauce and lay a slice of mozzarella over every steak.
Dust with a tablespoon of finely chopped parsley and allow the whole to tone up a little, covered, for a half minute, then serve. The cheese must be completely melted and bind the steaks.