Cook and prepare the ground beef in a large skillet on medium high heat, then add in the taco seasoning in accordance with the package instructions.
Add in the onions and peppers, let these cook for 5-10 minutes or until soft.
Stir in the diced tomatoes and tomato sauce.
While this is simmering, spiralize the zucchini, and then place in a colander with a sprinkle of salt. Let it sit for 10 minutes, then squeeze out as much liquid as possible.
Spray a 9x13-baking dish with nonstick cooking spray, and then evenly place the zucchini in the dish.
Top the zucchini with the meat mixture.
Lastly, sprinkle the cheese on top.
Bake for 30 minutes or until cheese is nicely melted.