Green Chili Sour Cream Enchiladas

20 corn tortillas
1 small cans green chili enchiladas sauce
1 small tub sour cream
1 lb chicken breasts
12 oz grated cheese (any blend)
1 tbs butter
1 tbs flour
cook chicken, shred. Melt butter in small saucepan on low heat, whisk in flour til combined. Add enchilada sauce and sour cream in a pan, whisk till sour cream is melted. set aside. Layer tortillas, chicken, cheese and sauce in 9x13 casserole dish. Bake 30 minutes at 375* covered, uncovered for the last 10 minutes.