Creamy White Chicken Chili

1 lb. boneless, skinless chicken breasts, cut into 1/2" cubes
1 medium onion, chopped
1 1/2 Tbsp garlic powder
1Tbsp oil
2 cans (15 1/2 ounces each) white beans, rinsed and drained
1 1/2 cups chicken broth
2 cans (4 oz each) chopped green chilies
1 tsp salt
1 tsp ground cumin
1 tsp dried oregano
1/2 tsp pepper
1/4 tsp cayenne pepper
1 Cup sour cream
1/2 cup heavy cream

In a large saucepan saute chicken, onion  and garlic powder in oil until chicken is no longer pink. Add beans, broth, chilies & seasonings. Bring to a boil, then reduce heat and simmer uncovered for 30 minutes. Remove from heat and add sour cream and heavy cream. 

Serve with heated tortillas.