Preheat the oven to 350°F. Grease a shallow 3-quart casserole. In a large bowl, combine the carrots, zucchini, squashes, onion, and garlic with the browned beef. Stir in the mushroom soup and sour cream. Add the basil, salt, and pepper. Mix all of the ingredients together. Spread 1½ cups of the bread crumbs in the bottom of the casserole. Distribute the vegetable-and-meat mixture evenly over the crumbs. Top with the remaining crumbs. Bake for 35 minutes. Cover the dish if the casserole starts to dry out. Cool slightly before garnishing with chopped tomato.