3 medium chicken breasts

1 can green chilis, chopped
6 medium sized tomatillos
olive oil
2 cloves of garlic
(one quarter) cup flour
1 (three quarters) cup sour cream
a pinch of oregano
a handful of flour
2 cups chicken stock
salt and pepper
yellow onion
2 cups grated monterey jack cheese
12 flour tortillas

Preheat oven t0 350°F

Simmer the chicken breasts in a stockpot for 30 minutes or so till tender in lightly salted water.
Using tongs to remove and reserve stock.

In a frying pan, saute chopped tomatillos in olive oil, on high-ish heat so the skin sears.  Turn flame down, add minced garlic and drained green chilis.

In a cuisinart, with a metal blade, mix tomatillo mixture until smooth.

Melt a little more olive oil and a tiny spot of butter in another frying pan over medium heat.  whisk in flour, stirring to make a roux, add chicken broth, stirring so that it stays smooth.  Add  1 cup of sour cream and 8 tbs of tomatillo salsa.  Whisk until smooth and add a little salt and pepper to taste.

Make the filling in a bowl.  Combine chopped onion, 1 cup Jack cheese, remaining (three quarter) cup sour cream, shredded chicken, a generous pinch of oregano and salt and pepper.

In another frying pan, melt a little more olive oil and quickly saute lightly, the flour tortillas. 
Spread half the remaining tomatillo sauce over the bottom of a pyrex pan. 

Fill each flat tortilla with chicken mixture, then roll up the tortillas and place them in pyrex pan, seam-side down.  Cover with the remaining sauce and sprinkle with the rest of the jack cheese. 

Bake for 30 minutes. Serve with salsa or if you want to be a purist, serve with tomatillo relish salsa.
To make salsa dice tomatillos, onion, jalapeno (to taste), and lime and a little salt and pepper to taste and mix them all up in a glass or china bowl.  Refrigerate salsa.  And serve as a condiment.