For the Filling:
3 large yellow onions, chopped
3 tablespoons oil or butter
6 poached chicken breasts, pulled into strips
12 ounce canned green chilies, chopped
3 cups shredded jack cheese (reserve 1 cup for topping enchiladas)
10-12 corn tortillas, warmed to soften
3 tablespoons oil

For the Cheese Sauce:
3/4 cup butter
1/2 cup all-purpose flour
1-1/2 teaspoons salt
1-1/2 teaspoons white pepper
2 cups milk
1-1/2 cups chicken stock
1-1/2 cups sour cream
2 cups shredded jack cheese (Pepper Jack may be substituted for a spicier result)

To Serve:
1-1/2 cups bottled green chili sauce
3 medium tomatoes, chopped
1 avocado, sliced
A few sprigs of cilantro
Lime wedges, to serve
A large, rectangular baking dish, oiled

To make the cheese sauce, melt the butter in a saucepan, add the flour, and stir until a light brown. Add the salt, pepper, milk, and chicken stock. Cook until thickened. Add the sour cream and cheese. Season to taste. Preheat the oven to 375 degrees. Sauté the onion in oil until lightly browned. Add the pulled chicken, green chilies and 2 cups of jack cheese. Lay the tortillas flat and fill each one with about 1/2 cup of filling. Roll the tortillas and arrange in lines in the prepared dish. Pour cheese sauce over the top. Top with the remaining cheese. Bake in the preheated oven for about 30 minutes or until lightly browned. Garnish with green chili salsa, tomatoes, avocado, cilantro, and lime wedges to serve.