If the chicken isn't cooked, place in a pan of rapidly boiling water, cover, and reduce heat to simmer. Let cook for 20 minutes.
Remove chicken from heat, drain, cool, and shred.
If using another protein, shred or cube.
In a medium skillet, melt butter over medium heat.
Cook onion and bell pepper until soft, 5-8 minutes.
Transfer to a large bowl.
Add chicken, cheddar, roasted green chilies, salsa, cilantro, cumin, and chipotle peppers.
Season with salt and pepper to taste.
Preheat oven to 350°F
Grease a 9x13 inch baking dish. May need two.
Place one tortilla on a flat surface and place about ⅓ cup of the chicken mixture just a little closer to you than the middle. Roll up and place, seam side down, in the prepared pan.
Repeat process until all filling is gone.
Sprinkle Monterey Jack over the enchiladas.
Combine heavy cream and chicken broth and pour evenly over the enchiladas.
Cover with foil and bake 30 minutes.
Remove foil and bake another 10 minutes more or until thoroughly heated and cheese is melted.
Let cool and set for 10 minutes before serving with avocado, cilantro, tomato and/or sour cream.