Market salad with ranch dressing

Ingredients

• Ranch dressing
• 2/3 cup store-bought mayonnaise
• 1 cup puhoi valley half & half plus a little extra
• 4 tablespoon crème fraiche
• 2 tablespoon white vinegar
• 1 teaspoon ground black pepper
• 1 teaspoon onion salt
• pinch cayenne pepper
• 1 clove garlic, crushed
• 2 tablespoon finely chopped chives
• 2 tablespoon finely chopped flat leaf parsley
• To serve
• iceberg lettuce, cut into wedges