Heat oil in a large frying pan over medium-high heat. Add onion, garlic, and tomatoes; cook, stirring, for about 3 minutes. Add zucchini and cook until crisp-tender, about 3 minutes, and remove from heat. In a large bowl, blend eggs, bread crumbs, oregano, basil, cheeses, salt, pepper, and the zucchini mixture. Spread in a greased 9x13-inch baking pan. Sprinkle with sesame seeds. Bake in a preheated 325 degrees F oven for 30 minutes, or until set when lightly touched in the center. Cool on a rack for 15 minutes. Cut into 1-inch squares and serve warm or at room temperature. Can also be refrigerated and served cold.