Bring a large pot of water to a boil and break the pasta noodles into small segments. Add spaghetti and cook, stirring occasionally for 8 to 10 minutes, drain and place into a big bowl. In a skillet over medium high heat, saute the onions, green peppers and beef until the beef is browned and the vegetables are soft. Remove from heat and drain

Replace the mixture back into the skillet and add; tomatoes, mushrooms and oregano, Simmer uncovered for 10 minutes while the oven preheats to 350 degrees. Grease a big casserole dish (9x13 or better)and place half of the pasta in the bottom of the prepared dish, top with half the meat mixture and sprinkle with 1 cup of the cheese.

Repeat by again topping with the other half of the meat mixture and then topping with another cup of cheese. In a medium bowl, mix together the mushroom soup and the water, making sure that this is blended well and smooth, then pour the soup mix over the casserole and sprinkle with parmesan cheese. Bake in the oven for 30 to 35 minutes, remove and let stand 10 minutes before serving