In frying pan, brown ground beef until crumbly. Drain excess fat. Add onion, garlic salt, and tomato sauce. Cook, covered, over low heat just long enough to heat thru. Remove from heat and set aside. Combine sour cream, cottage cheese, olives and green chilies. Set aside. Crush tortilla chips slightly, reserving a few whole chips for garnish, if desired. Place half of the chips in a well buttered 2 1/2 quart casserole dish. Add half of the meat mixture; cover with half of the sour cream mixture and sprinkle with half of the grated cheese. Repeat layers. Bake uncovered in 350~ degree oven 35 minutes or until bubbling hot. Garnish with saved tortilla chips. Serve with sour cream. Reduce or eliminate chilies for children or sensitive palates.