Spread the oil generously on 4 gratin portion forms. Season the canned tomatoes with salt and pepper and spread them on the bottom of the tins. Scatter oregano on top and layer the mozzarella in a wreath shape in the molds.
Bake in the middle of the oven preheated to 220 ° C until the cheese begins to melt. Take the molds out of the oven. Beat in 1 egg each (it should stay whole, like a fried egg), lightly salt and pepper. Spread the Parma ham strips over the top and immediately put them back in the hot oven. Bake again until the egg white has set.
Then sprinkle the chopped basil on top and serve immediately. If you like, you can squeeze some garlic into the tomatoes. If you like it spicy, you can also add some chilli to the tomatoes.