In a heavy skillet, brown the beef and onion, drain well. Season to taste with salt and pepper.
Spread refried beans in an 11x13-inch casserole; top with meat mixture and
sprinkle with chiles, then shredded cheeses. Drizzle salsa or sauce evenly over all.
Bake at 400° for 20 minutes.
Remove from the oven and sprinkle green onions, chopped tomato and olives over all. Mound
avacado or guacamole in center; top with a dollop of sour cream. Serve with tortilla chips.
Serves 4.