Cook macaroni according to package instructions; set aside.
16 ounces macaroni noodles
While pasta is cooking, heat oil in a large, deep skillet. Add onion, peppers and garlic plus a pinch of salt and pepper and saute until tender, about 5-6 minutes.
1 tablespoon extra virgin olive oil, 1 medium onion, 1 green bell pepper, 2 cloves garlic, salt and pepper
Add ground beef and oregano to the pan. Cook until beef is browned through, using a wooden spoon to break into bite-sized pieces. Continue until beef is golden brown, about 8-10 minutes. Stir in tomato sauce and diced tomatoes and heat until cooked through. Check for seasoning and adjust accordingly.