Preheat oven to 350 degrees F. In a large bowl mix together sour cream, cream cheese, refried beans, onions and taco seasoning. Put mixture in an 8 by 8-inch glass dish. Sprinkle with cheese. Bake for 20 minutes until cheese is melted. Serve with tortilla chips.
Recipe courtesy Bret Boone, Seattle Mariners, from "Starters and Closers" by Karen Moyer, ed., benefiting the Fred Hutchinson Cancer Research Center