Combine cabbage, onions, Ramen noodles, and water chestnuts.
Preheat oven to 275. Place sesame seeds and almonds on two separate cookie sheets. Toast seeds and nuts until slightly browned, about 5 minutes for seeds and 10 to 15 minutes for almonds. Cool, then add sesame seeds and almonds to the salad.
Whisk all dressing ingredients together. Pour over salad.