Preheat the oven to 350 degrees. In a large skillet, cook the ground beef over medium heat until browned. Add the onion and the green pepper and cook until the vegetables are tender, about 5 minutes. Add the tomatoes and the Worcestershire sauce, oregano, salt and pepper. Bring to a boil, then turn the heat to low. Simmer for about 15 minutes.
Boil water in a medium pot. Stir in the noodles and cook for about 8 minutes, until tender. Drain. Return the noodles to the pot and pour the tomato mixture over the noodles and stir until blended.
Spray baking dish with cooking spray and pour the mixture in. Sprinkle with cheese and bake for about 15 minutes, until the cheese is melted.