Preheat and Prep: Preheat your oven to 375°F (190°C). Grease a large casserole dish with a little oil or non-stick spray and set it aside.

Cook the Beef: In a large skillet, heat the vegetable oil over medium heat. Add the lean ground beef and salt. Cook until the beef is browned and no longer pink, breaking it up into crumbles as it cooks. Drain any excess fat if necessary.

Sauté the Vegetables: Add the chopped onion, minced garlic, paprika, Italian seasoning, onion powder, garlic powder, and a pinch of black pepper to the beef. Cook for roughly 3 to 4 minutes until the onions become clear and aromatic.

Add the Bell Peppers: Stir in the chopped bell peppers and cook for another 2-3 minutes until they begin to soften.

Mix in the Sauce and Zucchini: Pour in the tomato sauce and water, stirring to combine. Add the sliced zucchini to the mixture and gently stir to coat all the pieces with the sauce. Bring the mixture to a simmer and cook for about 5 minutes until the zucchini starts to soften.

Add the Rice: Stir in the instant rice, making sure it is evenly distributed throughout the casserole mixture.

Transfer and Bake: Transfer the mixture into the prepared casserole dish. Evenly distribute the shredded cheddar cheese across the surface. Cover the dish with aluminum foil.

Bake: Place the covered casserole dish in the preheated oven and bake for 20 minutes. Take off the foil and continue baking for another 10 to 15 minutes, or until the cheese is melted and bubbling, and the casserole is thoroughly warmed.

Serve: Remove from the oven and let the casserole rest for a few minutes before serving. Enjoy this hearty, unstuffed zucchini casserole with a fresh side salad or some crusty bread.