Combine flaked fish, celery green onions, water chestnuts, mayonnaise, lemon pepper and garlic salt in a large bowl and stir to mix. Coat a baking dish with vegetable spray. Spread fish mixture in baking dish and bake in a preheated oven for 20-30 minutes or until thoroughly hot. Serve as a dip or spread with potato chips, crisp crackers or toasted French bread slices.
*Could also be served as a casserole by topping with 1 cup of crushed potato chips