Two layers in the casserole; two more to go
Roast 6-8 or more large green chiles (Anaheim type) under the broiler or over an open flame until charred all over. Place in a closed plastic bag or covered Tupperware container for ten minutes or so. You should then be able to peel them easily.
Take off the stem ends and take out seeds and membranes (leave some in if you want—they’re the hot part).
Beat three egg whites until stiff, adding ½ tsp. salt. You can leave out the yolks for a very low fat version, but I stir them up and fold them into the beaten egg whites.
In a greased oblong casserole, place half the egg white mixture, all the chiles, sprinkle with as much cheese as you want, then cover over with the remaining egg whites, spreading them all the way to the edges to seal. Bake at 350 for 25 minutes or so until brown.