Combine the beef, sausage, onion and garlic in a 3-qt. microwave-safe dish. Cover and microwave on high for 4-5 minutes, stirring once to crumble meat. Drain. Add the tomatoes, corn, tomato paste, olives, chili powder and salt; mix well. Cover and microwave on high for 4-6 minutes or until heated through.
Whisk egg in a large bowl; add milk and cornbread mix. Stir just until moistened. Spoon over meat mixture; sprinkle with paprika.
Microwave, uncovered, on high for 14-16 minutes or until a toothpick inserted in the center of the cornbread comes out clean. Sprinkle with cheese.