Preheat oven to 350 degrees. Spray casserole dish lightly with cooking spray and set aside.
Melt butter in a large sauté pan over medium-high heat. Add the onion and cook for 5 to 7 minutes, or until onions are translucent in color. Add in chilis and cook for another minute or two, stirring to combine.
Turn heat down to medium and stir in cream cheese and chicken, cooking until cheese melts and ingredients are well combined. Remove chicken cheese mixture from heat.
Spoon 3 to 4 tablespoons of chicken cheese mixture down the middle of a tortilla shell and roll up the shell. Nestle each roll, seem side down, in prepared casserole dish.
Sprinkle shredded Monterey Jack cheese over the tortillas. Sprinkle half a tablespoon of cumin over shredded cheese, then drizzle whipping cream over entire dish.
Bake chicken enchiladas for 45 minutes, or until cheese is melted and bubbly. Sprinkle with more chilis if desired.
Notes
Freezer Option: These enchiladas freeze very well. Simply take the dish out of the freezer and place it in the oven as it preheats to prevent the cold casserole dish from cracking. Heat at 350 degrees for 45 minutes, or until enchiladas are heated through.