Step 1: Preheat oven to 375°F (190°C).
Step 2: Cook macaroni according to package directions until al dente, then drain.
Step 3: In a large skillet, heat olive oil over medium heat and cook onion until softened, about 5 minutes.
Step 4: Add ground beef and garlic to skillet, cooking until beef is browned, about 8 minutes.
Step 5: Stir in tomato sauce, beef broth, oregano, salt, and pepper, simmering for 5 minutes.
Step 6: In a large bowl, combine cooked macaroni, beef mixture, sour cream, and half of each cheese.
Step 7: Transfer mixture to a greased 9×13-inch baking dish and top with remaining cheeses.
Step 8: Bake uncovered for 20-25 minutes until bubbly and cheese is golden.
Step 9: Let cool for 5 minutes before serving.