Preheat oven to 375°F and grease a 9x13” baking dish.
In a pan, sauté onions and garlic in olive oil until soft, about 2-3 minutes.
Add green chiles, beans, water, bouillon, and cumin. Simmer for 15 minutes, then add chicken and cook until thickened.
For the sauce, melt butter in a pan and cook onions until translucent. Stir in flour and cook for 1 minute.
Slowly whisk in chicken broth and cook until thick, then add green chiles, jalapeños, and salt. Stir in sour cream.
Spread 1/4 cup of the sauce in the baking dish. Fill tortillas with chicken and bean mixture, then roll and place seam-side down.
Pour remaining sauce over the enchiladas, top with cheese, cover with foil, and bake for 20-30 minutes.
Remove from the oven, garnish with cilantro or scallions, and serve!