First, place tortillas in a deep dish and pour one can of chicken stock over so that they can soak while you prepare the remainder of the dish.
(use cold stock or tortillas will get mushy) Melt butter in saucepan, stir in flour and then add one can chicken stock and pour off remaining stock from tortillas into this saucepan.
Cook until slightly thickened over med-high heat and then add jalapenos.
Turn heat off then stir in sour cream- mix thoroughly.
Layer ingredients in a 9 x 13 casserole as follows: four (4) tortillas to completely cover bottom (I tear them in half to cover),1/3 of the chicken, 1/3 of the sauce 1/3 of the onions and then 1/3 of the cheese; repeat until all layers are used ending with cheese on top.
Sprinkle with paprika Cover tightly and place in refrigerator overnight (it will work if left refrigerated for 8 hours).
Bake at 350 degrees for one hour (remove cover half-way through baking).
Probably best to let stand for 15- 20 minutes before cutting into serving pieces.