Question: What are the optional ingredients for Warm Chinese Chicken Salad?
SQL: SELECT T3.name FROM Recipe AS T1 INNER JOIN Quantity AS T2 ON T1.recipe_id = T2.recipe_id INNER JOIN Ingredient AS T3 ON T3.ingredient_id = T2.ingredient_id WHERE T1.title = 'Warm Chinese Chicken Salad' AND T2.optional = 'TRUE'