Heat a pan over medium-high heat and cook the chicken until lightly brown. Remove from the heat and allow to rest while simmering.
Add the enchilada sauce, Rotel, chilies, onion and water. Reduce the heat to simmer and cover for 8 to 10 minutes or until onions have softened.
Add the chicken to the sauce. Add in salt, pepper, garlic powder. Stir and continue to simmer for an additional 10 minutes uncovered or until most of the liquid has reduced.
Garnish with sour cream, avocado and shredded cheese (optional)