Preheat oven to 350F.
Cut the center out of the zucchini and chop what you remove.
Drizzle hollowed zucchini with oil and sprinkle with salt and pepper. Place zucchini in a casserole pan, bake for 25 minutes or until done.
Brown ground beef over medium heat and season to taste.
Saute tomato, pepper, onion, and chopped zucchini in a pan with olive oil over medium heat. Season to taste and cook until veggies are almost done but still firm.
Remove the zucchini from the oven and fill with sauteed veggies, top with cheese. Return to oven and allow the cheese to melt. Serve hot.