In a large, cast-iron skillet over medium heat, sauté the onions, garlic, green pepper and tomatoes until softened. Fold in basil and remove to a bowl.
While the onions and peppers are cooking, combine zucchini, egg, flour, salt and pepper and stir well.
Drizzle a little EVOO into the same skillet the onions and peppers were cooked in. Drop 4 equal mounds of the zucchini egg mixture onto the skillet and cook over medium heat for about 2 minutes on each side.
Top each of the zucchini-egg rounds with some of the cooked tomato mixture and shredded cheese. Pop under the broiler until golden brown and bubbly, 1-2 minutes.