1. Roast or broil the chilies.
2. Peel, stem and seed them. Set aside.
4. In a small bowl, stir the egg yolks together. Add the flour, grated onion, pepper, salt garlic salt and water.
6. In a medium bowl, beat the egg whites until stiff. Add the yolk mixture and stir to combine.
7. In a small casserole dish, layer 4 of the chiles, top with about 1/3 cup grated cheese.
8. Top with about 1/3 of the egg mixture.
9. Repeat this for two more layers.
10. Bake for 20 minutes until the casserole is bubbling and the top is lightly browned.
11. Serve with a fresh tomato salsa.