Time: 45 Minutes Serves: 6 (keeps very well in the fridge for cold leftovers) Ingredients: 12-18 medium Yukon Gold Potatoes 32 oz. Sour Cream 16 oz. Heavy Cream 1 tsp. Dijon Mustard 1 tsp. Salt 2 tsp. White Pepper 2 tsp. Black Pepper 1 Bunch Watercress 2 Bunches Spinach 1 Bunch Parsley 3 Stalks Tarragon…