Spring Greens Salad with Traditional Ranch Dressing

Name: Spring Greens Salad with Traditional Ranch Dressing
Ingredients: 1 cup mayonnaise; 1/2 cup sour cream; 1/4 cup buttermilk; 1 tablespoon apple cider vinegar; 1 teaspoon Dijon mustard; 1 tablespoon thinly sliced chives; 1 tablespoon roughly chopped fresh parsley; 2 cloves garlic, finely minced; 2 bunches pencil-thin asparagus, woody ends trimmed, stalks cut on the bias into 1/2-inch pieces (3 to 4 cups); 3 cups spring lettuce mix; 3 cups baby spinach, stems removed; 1 cup watercress; 2 shallots, thinly sliced into rounds; 1 pint grape or cherry tomatoes (multi-color if available), halved; Kosher salt and freshly ground black pepper