Preheat oven to 350 degrees
Heat olive oil in a large skillet over medium heat.
Saute mushroom, garlic, onion and green pepper until soft
Add in tomatoes, olives and Italian seasoning and stir until blended
Add ground beef and cook, uncovered, until no longer pink
Spray a 9x13 baking dish with cooking spray.
Add half of the cooked spaghetti, then top with half of the meat mixture
Sprinkle 1 cup cheddar on top, then repeat layers.
Stir mushroom soup and water together and pour over top.
Sprinkle with parmesan cheese and bake uncovered for 30-35 minutes