In a skillet over medium heat, cook the ground beef until it's browned and crumbled. Drain any excess fat.
In the same skillet, add chopped onion and green bell pepper. Sauté until they're tender.
Season the mixture with dried basil, dried oregano, garlic powder, salt, and pepper. Stir well.
Add the drained diced tomatoes to the skillet. Mix everything together.
Transfer half of the zucchini mixture into a greased casserole dish.
Sprinkle half of the shredded cheddar cheese over the zucchini layer.
Add the remaining zucchini mixture on top of the cheese layer. Finish with the remaining cheese.