Heat a large sauté pan with oil, add chicken and garlic and sauté for 2 minutes over medium high heat until chicken is golden brown.
Add onion, bell pepper, tomato and spices and cook until vegetables are tender. Add chicken stock and chiles. Cook until stock is almost gone.
Lightly coat an 8 x 8-inch glass baking dish with cooking spray. Place 1 tortilla in bottom of pan. Spread 1/2 of chicken mixture over tortilla. Top with 1/2 of cheese. Then top with remaining tortilla, chicken mixture and cheese.
Bake for 15 to 20 minutes or until cheese is melted and lightly browned on top. Cut into 4-6 servings.