In a Dutch oven or heavy-bottomed pot, heat the oil over medium-high heat.
Add onions and cook about 3 minutes. Add garlic and cook for about a minute more.
Add chicken and cook for 10 minutes or until the chicken is done.
Stir in remaining ingredients and broth; bring to a boil.
Cover, reduce heat, and simmer for 30 minutes (or more). Stir occasionally and adjust for salt as needed.
Serve with garnishes such as grated sharp cheddar, sour cream, and chopped cilantro.