If using ground meat, heat a large skillet over medium heat and add a little bit of oil. Cook until meat is browned, breaking up chunks as you go along.
Add the meat and remaining ingredients to a large Crock-Pot. Mix well.
Cover and cook on low for 8-9 hours, or high for 6-7 hours.
If using chicken breast: when there is about 1 hour left, remove the chicken, use two forks to shred it, and then return the chicken to the Crock-Pot to continue cooking.
Dish out into bowls and top with plain Greek yogurt, diced avocado, cheese, or desired toppings.