Heat oil in 6-quart stock pot. Stir fry pork cubes 7 minutes on high heat. Add onion; stir fry 5 minutes.
Stir in remaining ingredients except sour cream and cilantro. Bring to a boil over medium-high heat; boil 15 minutes. Reduce heat and simmer 30 minutes, stirring occasionally.
Remove chili from heat. Stir in sour cream and cilantro just before serving.