Add the chicken to the slow cooker and cover with the lime juice, olive oil, garlic powder, cumin, salt, and pepper. Cover with the lid and cook on high for 2 hours
Add the sliced peppers and onions, season with salt and pepper, and cook on high for 30 minutes - 1 hour more (depending on how crisp you like your peppers and onions)
when finished, remove the peppers and onions to a platter. Remove the chicken and slice. Spoon some of the remaining juices over the chicken.
Serve with an extra squeeze of lime, slices of avocado, Mexican Crema, and low carb tortillas