1. Preheat your oven to 400F (200C). In a large bowl, toss together zucchini, red and yellow peppers, eggplant, oil, oregano, basil, salt and pepper until vegetables are coated. Transfer to a baking sheet. Roast, stirring once, for 25 min or until vegetables are soft.
2. Meanwhile, whisk together milk, cream and eggs. Cut each slice of bread diagonally in half.
3. Arrange 8 bread halves on the bottom of a buttered 9 X 13-inch (3 L) baking dish. Stir tomato into the roasted vegetables. Scatter half the vegetable mixture evenly over the top. Sprinkle with half of the Mozzarella and half of the Asiago.
4. Arrange remaining bread halves on top. Scatter with remaining vegetables.