Heat the olive oil in a large pot over medium heat.
Add onions and saute until soft, or for about 5 minutes.
Add all other remaining ingredients and stir together. Increase the heat to medium high and bring to a boil. Cover and reduce heat to medium low so that the mixture simmers. Cook for 15-20 minutes, or until rice is fluffy and liquid is absorbed.*
Serve with salsa, cheese, and sour cream.