This recipe can be made with or without chicken. It is full of spinach, cheese, winter squash (or cauliflower for Keto) and green chilies; so it's rich and abundant if a meat-free entree is preferred/easier some night. The tortillas are high-protein, made from grass-fed eggs and chia seeds (or you can use other tortillas of choice).
Ladle 1 cup enchilada sauce into large slow cooker, or Instant Pot. Layer 2-1/2-3 tortillas over the sauce, tearing the last one to two tortillas so the pieces cover all the sauce and fit the shape of the cooking dish.
If using Crock Pot, place dish into base and set timer for 3.5 hours, on low heat. (Note: Pressure cookers vary in how hot they run; so cooking times will vary.)
If using Instant Pot, make sure rubber ring is in place. Seal lid and shut steam valve. Set "Manual" button to 55 minutes. When timer goes off, do a Natural Release of pressure for 30 minutes; then press "Cancel" button and do a Quick Release. It will be saucy, but use a butter knife to cut down and through tortillas (cut in sections like cutting a pie). I then use a ladle in one hand and large serving spoon in the other so I scoop big saucy sections onto each plate or into broad bowls.
Also serve Crock Pot version of finished casserole with broad serving spoon for scooping up the sauciness. Garnish each with desired condiments: grated cheese, fresh cilantro, sliced olives, shredded lettuce, pico de gallo salsa and/or sour cream.