Black Bean & White Cheddar Frittata

Preheat broiler. In a large bowl, whisk the first 6 ingredients until blended., In a 10-in. ovenproof skillet, heat oil over medium-high heat. Add peppers and green onions; cook and stir 3-4 minutes or until peppers are tender. Add garlic; cook 1 minute longer. Stir in beans. Reduce heat to medium; stir in egg mixture. Cook, uncovered, 4-6 minutes or until nearly set. Sprinkle with cheese., Broil 3-4 in. from heat 3-4 minutes or until light golden brown and eggs are completely set. Let stand 5 minutes. Cut into wedges. Serve with toppings as desired.