Mix the tomatoes, mozzarella balls, basil and 1 teaspoon olive oil in a bowl. Season with salt and pepper. Cover and let stand at room temperature for 25 minutes.
Heat 1 tablespoon of olive oil in a pan. Fry the eggs in it until the egg white has hardened, 1 - 2 minutes on each side.
Toast bread as you like.
Spread some avocado on bread, place a fried egg and ¼ of the caprese mixture on top. Proceed in this way until all 4 toasts are ready. Drizzle with a little salt, pepper and olive oil. Serve immediately.