Preheat oven or prepare microwave-safe dish.

Boil macaroni according to package directions until al dente.

While macaroni cooks, brown ground beef in a skillet over medium heat.

Drain any excess grease from the ground beef.

Add chopped onion, green pepper, and oregano to the skillet with the ground beef.

Sauté until the onion and green pepper are softened, about 5 minutes.

Pour in the tomato sauce and bring to a simmer.

Let simmer for 5 minutes, stirring occasionally.

In a casserole dish, combine the cooked macaroni, ground beef sauce, mozzarella cheese, and cheddar cheese.

Mix well to ensure all ingredients are evenly distributed.

Sprinkle additional cheese on top of the casserole.

Microwave for 5-10 minutes, or bake in a preheated oven at 350°F (175°C) for 20-25 minutes, or until the cheese is melted and bubbly.