1. Toss watercress with goat cheese in a large salad bowl. Cut bell pepper lengthwise into thin strips and set aside.
2. In a small bowl, whisk buttermilk with mayonnaise until smooth. Stir in parsley and garlic. Season dressing with salt and pepper.
3. Pour 1/4 cup of dressing over watercress, toss well and arrange on individual salad plates. Garnish with red pepper strips. Serve remaining dressing on the side. Or serve salad in a large bowl with dressing on the side.