Preheat oven to 425°F and grease a 9×13 baking dish.
Heat water with bouillon until dissolved for broth.
Sauté onion 7 minutes, add garlic and cook 1 minute.
Mix in shredded chicken, salt, and pepper.
Fill tortillas with chicken and Monterey Jack, roll into dish.
Whisk butter and flour, slowly add broth and cook until thick.
Stir in sour cream, green chilies, seasoning, and cheese.
Pour sauce over enchiladas, top with cheese, bake 20 minutes until bubbly.