Preheat a large skillet to medium-high heat with the butter. Add the chicken and sprinkle evenly with the cumin, chili powder, garlic powder, and onion. Cook the chicken for about 5 minutes on each side until cooked through. Remove the chicken to a plate to cool, then shred into large pieces.

When the chicken is out of the skillet, reduce the heat to medium and add the onion and jalapeno. Cook for 3 minutes, stirring, until the onion has softened slightly, then add the garlic and cook for one minute more. Pour the enchilada sauce into the veggies, then return the shredded cooked chicken to the skillet.

Stir everything together and taste; add salt if you'd like.

Serve the chicken on buns with any toppings you'd like. Yum!