- Brown beef with onion in 10-inch oven-proof skillet with lid. Stir in tomatoes, soy sauce and 1 cup water; bring to boil. Stir in macaroni. Reduce heat to medium-low; cover and simmer about 12 minutes, or until macaroni is tender.
- Meanwhile, melt butter in small skillet. Remove from heat and add panko, stirring until well coated.
- Preheat broiler.
- Add cheese and corn to macaroni mixture. Increase heat to medium; cook, stirring, until cheese melts. Remove from heat; spoon bread crumbs mixture evenly on top.
- Broil about 1 minute, or until topping is lightly browned.