Heat oven to 400°F. Line cookie sheet with foil. Arrange tortilla chips on cookie sheet, overlapping slightly.
In 10-inch skillet, heat oil over medium heat. Cook bell pepper in oil 3 to 4 minutes or until tender. Add butter and garlic, stirring until butter is melted. Add chicken. Cook 2 minutes or until thoroughly heated. Remove from heat; stir in beans. If desired, season to taste with salt and pepper.
Spoon chicken mixture over chips. Sprinkle with cheese. Bake about 4 minutes or until cheese is melted. Sprinkle with cilantro and onions. Serve with salsa.