In a skillet, melt butter and briefly saute shredded chicken. Add onion and diced chiles. Cook for a few minutes. Cover, set aside.
In a saucepan, heat half and half, stir in seasonings, bring to a slow boil. Add chicken mixture, blend thoroughly, cover and simmer for a few minutes.
Preheat oven to 350 F. Lightly grease a 2 quart casserole dish and line with corn torilla triangles. Then add portion of chicken over torilllas. sprinkle with jack cheese, add another layer of torillas, then repeat until all ingredients are used up.
Transfer casserole into greased dish, sprinkle with cheese and bake for 35 minutes. Garnish with sliced olives, return casserole to oven and leave for five minutes. Serve warm.