Cook the millet in 3 cups of water until all water is absorbed, 30-45minutes. Fluff with a fork and allow to cool slightly.
In a very large bowl, combine millet, black beans, tomatoes, and onion.
Peel several strips from the cucumber (it should look striped) and cut itlengthwise into four pieces. Remove the seedy part from the pieces and cutthem into 1/2 inch slices. Add the cucumber to the salad.
Mix all dressing ingredients until well-blended. Pour over the salad andtoss to blend. Cover and refrigerate until the salad is very well chilled.
Serve on lettuce leaves or stuff into pita breads.