Prep/total time: 30 minutes | Yield: 6-8 servings

2 pounds ground beef
1 medium onion, chopped
1 bottle (8 ounces) taco sauce
6 corn tortillas (6 inches), halved and cut into 1-inch strips
2 cups (16 ounces) sour cream
1 cup (4 ounces) shredded cheddar cheese
1 cup (4 ounces) shredded part-skim mozzarella cheese

Crumble beef into a large microwave-safe dish. Stir in onion. Microwave, uncovered, on high for 6-7 minutes or until meat is no longer pink, stirring and draining every 2 minutes. Stir in taco sauce and tortillas.

In a greased 2-1 /2-qt. microwave-safe dish, layer half of the beef mixture, sour cream and cheeses. Repeat layers. Cover and cook at 70% power for 7-9 minutes or until heated through. Let stand for 2-4 minutes before serving.