04For sauce, in the same pan melt 3 tablespoons butter.
05Stir in flour, coriander and salt.
06Stir in chicken broth all at once.
07Cook and stir till thickened and bubbly.
08Remove from heat.
09Stir in sour cream and 1/2 cup of the cheese.
10Stir 1/2 cup of the sauce into the chicken mixture.
11Fill each tortilla with about 1/4 cup of the chicken mixture.
12Roll up and arrange in a 13x19x2 baking dish.
13Pour remaining sauce over and sprinkle with remaining cheese.
14Bake, uncovered in a 350 oven about 25 minutes or until bubbly.
15Can be made ahead of time and frozen. Place a large sheet of heavy duty foil in your baking dish with enough foil over the end to fold up and over the frozen casserole. Make the casserole up until you are ready to bake it. Freeze it solid. Remove frozen casserole from your dish and encase in the excess foil for storage. This frees up the dish for other meals. When you wish to heat it, remove foil from the still frozen casserole, and place back into the dish that you froze it in initially to thaw; bake as directed.