The one from Chuy's actually sounds pretty good.
Chuy's Hatch New Mexican Green Chile Sauce
Serve this great sauce over enchiladas, grilled pork tenderloin or other grilled meats and poultry, or as a side with beef tacos. From Chuy's Restaurant in Austin, TX.
3 tablespoons corn oil
2 tablespoons all-purpose flour
1 cup onions, chopped
2 teaspoons minced garlic
2 cups ROASTED New Mexican green chilies, peeled/seeded/chopped
2 cups beef broth
1 teaspoon salt
In heavy-bottomed sauce pan, saute onions in corn oil until they begin to brown.
Add garlic and cook another 2 minutes.
Stir flour in with onions and garlic so that it thickens.
Add chopped chilies, beef broth and salt and mix well.
Bring to a boil and simmer 10 to 15 minutes to allow mixture to reduce.
The sauce should be thick enough to bind chilies and onions together.
Sauce can be refrigerated for three days, or frozen.