Preheat the oven to 350 degrees.
In a large pan over medium high heat, add 2 tablespoons olive oil. Add onion and sauté until translucent, about 3-4 minutes.
Add diced chicken and green chilis to the pan. Sauté until the chicken is cooked through, about 7 - 8 minutes. Reduce heat to medium.
Stir ¼ cup enchilada sauce and refried beans into the pan. Heat 2-3 minutes, until well combined.
Drizzle ¾ cup of the enchilada sauce into a 9-inch by 13-inch baking dish. Spread to cover the bottom.
Assemble the enchiladas: on a dinner plate place one flour tortilla. Spoon about ½ cup of the chicken mixture into the tortilla and spread into a line running down the middle of the tortilla, leaving an inch on each end.
Wrap the tortilla and place the seam side down into the prepared pan.
Pour the remaining sauce over the top of the enchiladas and sprinkle evenly with the cheese.
Bake, uncovered, in the preheated oven for 20 minutes. The cheese should be melted and the edges of the tortillas barely crispy.
Optionally garnish with chopped cilantro.