White Bean Chicken Chili

1 med diced onion 2 tsp garlic powder 2 cans Costco canned chicken 4 cans great northern beans rinsed 2 can chicken broth - 14.5 oz each 4 4-oz. cans chopped green chili's (Hatch's) 2 tsp salt 2 tsp cumin 2 tsp dried oregano 1/2 tsp pepper 1 cup sour cream 1 cup whipping cream Add sour cream and whipping cream just before serving. Serves 10.