Crunchy Cauliflower Salad

1 medium head cauliflower
1 c sliced radishes
1/2 c sliced green onion
1 (8-ounce) can sliced water chestnuts, drained
3/4 c sour cream
3/4 c mayonnaise
2 tbs caraway seeds
1 (0.37-ounce) package buttermilk salad dressing mix

Wash the cauliflower, and break into flowerets. Combine cauliflower and next 3 ingredients in a medium mixing bowl; toss gently.
Stir together remaining ingredients; pour over vegetables, and stir well. Spoon into serving bowl; cover and chill before serving.