We've lightened this popular potluck classic with a dressing of reduced-fat mayo and yogurt. To speed preparation, use shredded broccoli slaw from the produce aisle.
1/2 cup finely diced red onion, (1/2 medium)
Cook bacon in a large skillet over medium heat, turning frequently, until crisp, 5 to 8 minutes. (Alternatively, microwave on High for 2 1/2 to 3 minutes.) Drain bacon on paper towels. Chop coarsely.
If using whole broccoli, trim about 3 inches off the stems. Chop the rest into 1/4-inch pieces.
Whisk yogurt, mayonnaise, vinegar, sugar, salt and pepper in a large bowl. Add water chestnuts, onion, bacon and broccoli; toss to coat. Chill until serving time.