Rub each piece of chicken with oil and season with salt and pepper.
Roast chicken thighs or breasts in oven at 400; 30 minutes for thighs and 20 for breasts. Leave oven on at 350 when finished for later cooking.
While chicken roasts, heat pan over medium heat. Saute garlic in olive oil for about 30 seconds until fragrant. Add mushrooms and saute for 3-4 minutes (do not salt mushrooms or they become mushy). Add spinach and saute for 2-3 minutes longer. Drain any liquid.
Add cooked chicken and 1 cup of cheese to mushrooms and spinach.
Put chicken stock in shallow dish/deep plate that is large enough to accomodate the tortillas.
Heat flour tortillas in a pan for about 1 minute or until tortilla is hot and pliable.
Dip tortilla in chicken stock.
Lay tortilla crosswise in 9x13 pan long ways and fill with about ⅓ cup of chicken mushroom filling. Roll the tortilla rather tight, putting seam side down in the pan.
Continue until pan is filled, using second pan (or save ingredients).
Top enchiladas with remaining cheese. Top with desired sauces outlined below (or none at all).
Bake for 15 minutes at 350.
The base of this is a very "neutral" enchilada that can be complimented as you choose. You can bake it plain and then top it with sauce (Hatch is a good brand). Another delicious option is to blend a brick of light cream cheese with a jar of salsa verde and a cup of chicken stock (aka as "enchiladas suiza- you can google for other ways to prepare). Regardless of the sauce you choose, coat your tortillas in and cover your enchiladas with it before baking for best flavor.