For sauce: Melt butter in a medium saucepan. Whisk in flour, then milk, water, and chicken bouillon. Add garlic, cumin, and half the can of green chilies. Stirring constantly, bring to a boil and boil for at least one minute. Set aside.
For filling: Combine chicken, beans, green onions, sour cream 1/2 cup of mozzarella cheese, half the can of green chilies, cumin, pepper in a large bowl. Stir together and add about 1/2 cup of the sauce (enough of the sauce to make it all stick together well).
Spread a thin layer of sauce on the bottom of a greased 9x13" pan. Fill each tortilla with about 1/3 - 1/2 cup of filling, and place seam side down on top of the sauce.
Pour remaining sauce over the top. Sprinkle with the cheese.
Bake at 375° for about 25 minutes, or till hot and bubbly.
Notes
We love using the uncooked Tortillaland tortillas from Sam's club and cooking them up fresh. They have the best taste and texture!
I like the crunchy cheese on the top, so I bake mine on the top rack of my oven.
I recommend serving these with sliced lettuce, diced tomatoes, avocado, and additional green onions.