Heat a large skillet over medium heat. Add the olive oil and zucchini and sauté until tender. Season with salt and pepper, then remove zucchini to a plate.
Add the ground beef, bell pepper, onion, and garlic to the skillet and sauté until browned.
Add the tomato sauce to the pan and season with oregano, parsley, basil, garlic powder, salt and pepper. Reduce heat to medium low and simmer for 10 minutes, stirring occasionally.
When sauce has reduced, add the rice, half the cheese, and zucchini and stir to combine. Top the skillet with remaining cheese.
Place a lid on the pan and cook for five to 10 minutes, until cheese on top is melted.