In a large bowl combine chicken, cream of chicken, sourcream, onion, and salsa. In an 8x8 dish add enough of the mixture to spread around and just cover the bottom (about 3/4 of a cup). Add cheese and olives to the remainder of the mixture in the bowl. Fill tortillas with the remainding mixture arranging them in the dish, they should fit together tightly. Top with cheese and olives. Bake at 350 degrees for 25-30 minutes