This is from Better Homes and Gardens, one of the better general-purpose cookbooks. Mine is copyrighted 1981. Unfortunately, the Food Nazis got ahold of later editions (for example they left the sour cream out of this recipe in later editions), so they're not as good.
Chopped Onion (don't overdo this or the green peppers)
1/2 Cup Chopped Green Pepper (it's attractive to mix pepper colors, like red and yellow)
2 tblspns Butter or margarine
2 Cups Chopped cooked chicken or turkey (I buy two roasted chickens at the deli counter in the supermarket and simply remove and shred the meat. One chicken would probably be enough.)
1 4oz can Diced green chili peppers, drained (these are mild, not hot, Mexican food section of grocery)
3 tblspns Butter or margarine
1/4 cup Flour
1 tspn Ground coriander (this is IMPORTANT. Do NOT omit this ingredient)
3/4 tspn Salt
2-1/2 cups Chicken broth (I like Swanson in the box)
1 cup Dairy Sour Cream
1-1/2 cups Shredded Monterey Jack cheese (I shred an 8oz package, which is actually 2 cups)
12 6-inch flour tortillas (I probably use about 10 of a larger size)
In a large saucepan cook onion and green pepper in the 2 tablespoons butter until tender. Combine onion mixture in a bowl with chopped chicken and the can of diced green chili peppers.
For sauce, in same saucepan melt the 3 tblspns butter. Stir in flour, coriander, and salt. Stir in chicken broth all at once (I don't know why, but it actually works best to dump all the chicken broth in at one time). Cook and stir until thickened and bubbly. Cook and stir 1 or 2 minutes more. Remove from heat and stir in sour cream and 1/2 to 3/4 cup of the cheese (I just throw in a handful of cheese). Stir 1/2 cup of the sauce into the chicken mixture. Fill each tortilla with about 1/4 cup of the chicken mixture (more, if using larger tortillas). Roll up and arrange in 13x9x2 inch baking dish (I use a glass dish, and I pour a little bit of the sauce into the bottom before I start putting in the enchiladas). Pour remaining sauce over enchiladas. Sprinkle with remaining cheese. Bake uncovered in a 350 deg oven 25 minutes or until bubbly (and the melted cheese is just starting to brown at the edge of the pan). Serves six (makes great leftovers, reheats well in microwave).