Preheat oven to 375 degrees. Spray an 8x8 inch baking dish with cooking spray, set aside.
Chop zucchini, bell pepper, and onion into bite-sized pieces. Set veggies aside separately.
In a large skillet or wok, add oil and heat over medium. Toss in onions and peppers and sauté for 5-6 minutes, allowing onion to soften. Add zucchini and saute for 3 more minutes. While it cooks, mince garlic. Add to veggies; toss together for one minute.
Add undrained tomatoes and cook for an additional 2 minutes.
Add bread crumbs, stir. Pour into prepared baking dish and sprinkle with cheeses. Cover with foil and bake for 30 minutes, removing the foil the last 5 minutes of baking to brown the top.
Serve with grapes on the side.