1. Spray large nonstick skillet with nonstick cooking spray. Heat over medium-high heat until hot. Add onions; cook and stir until tender.
2. Stir in beans, tomatoes, and corn. Bring to a boil. Reduce heat to low; simmer 5 to 8 minutes or until thoroughly heated.
3. Sprinkle with cheese; cover and cook an additional 1 to 2 minutes or until cheese is melted.
Nutrition Information Per Serving: 320 Calories, 11 g Fat, 1270 mg Sodium