Cut chicken into 1-1/2-inch pieces. Heat oil in large skillet over medium heat. Cook chicken, onion and garlic 5 minutes, stirring occasionally. Add 1/2 cup salsa and cumin. Cook 5 minutes, stirring occasionally.
Remove from heat; stir in 1 cup cheese. Spoon 1/4 cup mixture evenly down center of each tortilla. Roll up and place seam-side down in 11x7-inch baking dish. Spoon remaining 1 cup salsa evenly over tortillas.
Cover and bake in preheated 375°F oven 20 minutes or until hot. Uncover; sprinkle with remaining cheese. Let stand 5 minutes before serving. Garnish with lettuce, tomato and olives.