Combine the garlic powder, chili powder, cumin, onion powder, paprika, and salt in a small bowl. After patting the chicken dry, season the chicken on both sides, making sure to rub the seasoning mixture in.
Add the enchilada sauce and the Greek yogurt to the slow cooker and mix until well combined. Then add the onions, peppers (if using), and seasoned chicken. Cook on high for 3-4 hours or low for 5-6 hours.
2 medium onions, 15 ounces red enchilada sauce, 1/4 cup Greek yogurt, 1-2 bell peppers*
Thirty minutes before finished, shred the chicken with two forks. Add it back to the pot along with the cheese (if using) and cook for the final 30 minutes. When done, serve over rice or tortillas. I topped mine with cilantro and avocado!
3/4 cup shredded cheddar cheese*
Notes
If you don't have Greek yogurt on hand, you can substitute with sour cream.
My chicken usually takes about 4 hours to cook but time will vary based on your slow cooker.
After shredding, if time allows, I like to put the chicken back into the slow cooker for an additional hour so it can really soak up the juices and get tender.
Feel free to use any cheese you'd like! Mexican blend and mozzarella would both work well in place of cheddar if you prefer.