1. Season both sides of the chicken generously with salt and pepper.
2. In a large oven safe skillet, heat the avocado oil over medium heat, then add the chicken breasts. Cook for 6-8 mins per side (internal temp 165F). Remove the chicken from the skillet and set aside to cool. If the skillet is super hot and smoking, turn off the heat and let it cool down for a couple mins before proceeding.
3. Turn the heat on the skillet to medium and add the butter, onion, and jalapeño. Cook while stirring until the onions are starting to become tender and translucent (3-4 mins), then add the salt, chili powder, cumin, garlic, and flour.
4. Cook while stirring for 1 minute, then start gradually adding the milk 1/4 cup at a time, stirring to fully incorporate it before adding more. Once all the milk is incorporated, add the green enchilada sauce and diced green chilis. Mix and simmer uncovered over low heat for about 5 minutes while you shred the chicken.
5. Shred the chicken into small pieces with your fingers (or two forks) and add it to the skillet along with the white beans. Mix. Add the tortillas, mix, and cook for 2-3 more mins until heated through. Turn off the heat.
6. Spread everything in the skillet into one even layer and top with shredded cheese. Transfer the skillet to the oven and broil for 2-3 mins until the cheese is melted and has golden brown spots. Sprinkle with fresh cilantro and enjoy with toppings :)
