Keto Green Chile Chicken Skillet

oil (avocado, coconut, lard, or tallow works great)1 lb chicken breasts 1/2 teaspoon onion powder1/2 teaspoon garlic powder1/4 teaspoon salt 8 ounces canned green chilis 1/2 onion, thinly sliced 4 ounces cream cheese1 cup Monterey jack cheese, grated