Combine all ingredients under the Soup heading (up to the tortillas) into the slow cooker. Cook on low for 6-8 hours or high for 3-4 hours.
Remove the chicken and let it rest until it's cool enough to shred. Shred it and add it back into the soup. Discard the bay leaf.
While the chicken is cooling, preheat the oven to 400°f. Brush both sides of the tortillas with oil and cut into 1-inch strips and place them on a baking sheet. Bake for about 8-12 minutes, turning them at the halfway point. Keep an eye on them they can go from crisp to burned quickly!
Serve the chicken soup with some of the tortilla strips and toppings of your choice.
Notes
Use red or green enchilada sauce. If you are using chicken thighs only, you might want to trim off some of the extra fat.