Put cast iron skillet in preheated oven for 2 minutes, until cheese is just melted. Remove and sprinkle with half of eggs, then top with additional layer of chips. Top with remaining eggs, beans, tomatoes, red peppers and finally, cheese. Put back in oven for another 3 minutes, until cheese is melted. Garnish with green onions, cilantro and avocado. Serve with sour cream and salsa if desired.