Making

Melt butter in large skillet. Add onions and green pepper. Saute until softened. 

Add tomatoes, mushrooms, olives, oregano, and thyme. Stir until combined. 

Add ground beef, in chunks, and stir it into the mixture. 

Cook over medium-low heat, stirring occasionally, until ground beef is completely done, about 15 minutes. 

While meat sauce is cooking, cook spaghetti according to package directions, using 1 teaspoon of salt. 

When done, save about 1 cup of the pasta water for later use. Drain spaghetti through a colander and set aside. 

In a medium-sized bowl, mix mozzarella cheese with Cheddar cheese. Now, start assembling casserole. 

Add enough of the reserved pasta water to the spaghetti for it to separate easily, and spread ½ of the cooked spaghetti in a large 10-inch by 15-inch by 2-inch baking dish that has been sprayed with cooking oil spray. (You may use 2 smaller baking dishes, adjusting the amounts accordingly). 

Next, spread ½ of the meat sauce over the top of the spaghetti. Then, sprinkle ½ of the mozzarella and Cheddar cheese mixture over the meat sauce. 

Repeat the layers, using the other half of the spaghetti, meat sauce, and cheese mixture. 

Now, make a topping: In a small bowl, stir together cream of mushroom soup and half-and-half. 

Drizzle over top of casserole. Sprinkle top of casserole with 1 cup of shredded Parmesan cheese. 

Bake in a preheated 350 degree (F) oven 30 to 35 minutes, until top is beginning to brown and meat sauce has been absorbed. Remove from oven. 

Serving

Let sit for about 10 minutes and then serve with sliced, toasted Italian bread, sprinkled with Parmesan cheese. Add a green salad, and you have a complete meal!