Preheat the oven to 400°F.
Pound the chicken cutlets until they are evenly thin. Squeeze the lemon and marinate the chicken cutlets with salt, pepper, and some lemon juice.
Peel and finely chop the onion and garlic. In a small pot, heat 1 tablespoon of olive oil and briefly sauté the onion and garlic.
Add the tomatoes and season with oregano, basil, salt, pepper, and a little sugar. Let the tomato sauce simmer over medium heat for about 10–15 minutes.
Meanwhile, set the flour in a deep dish, whisk the eggs in a second dish, and combine the breadcrumbs and grated Parmesan in a third dish.
Dredge the chicken cutlets in the flour, then dip them in the whisked eggs, and finally coat them in the breadcrumb-Parmesan mixture.
Heat the remaining olive oil in a large skillet and cook the cutlets over medium heat for about 3–4 minutes per side until golden brown. Meanwhile, slice the mozzarella.
Place the cutlets in a large baking dish, top each cutlet with tomato sauce, and cover with 1–2 slices of mozzarella.
Place the dish in the oven and bake the chicken cutlets for about 8–10 minutes, until the mozzarella is melted and lightly browned.
