Cook rice in water as directed on package.
Meanwhile, heat oil in medium saucepan over medium-high heat until hot. Add onion; cook and stir 1 minute. Reduce heat to medium. Add beans, chiles and taco seasoning mix; mix well. Cook just until mixture comes to a boil, stirring occasionally.
Add cooked rice; mix well. Spoon into serving dish. Serve with sour cream and cheese.