Barbecue chicken and smashed potato salad

INGREDIENTS: 12 (about 600g) baby desiree potatoes 1 bunch asparagus, trimmed, cut into 5cm lengths 4 bacon rashers, coarsely chopped 1/2 cup (125g) whole-egg mayonnaise 1/4 cup (60g) sour cream 2 tablespoons lemon juice 3 teaspoons Dijon mustard 1 tablespoon coarsely chopped tarragon 1 whole barbecue chicken, or you can use chicken pieces that have been cooked…