Shrimp with White Cocktail Sauce

Ingredients

• • 3 packages (3/4 lb/340 g each) large shrimp (16/20), shelled with tails intact, thawed (see note)
  • 1/2 cup (125 ml) sour cream
  • 1/4 cup (60 ml) mayonnaise
  • 2 tbsp tarragon leaves, finely chopped
  • 1 1/2 tsp (7.5 ml) prepared horseradish
  • 1 small shallot, finely chopped
  • 1 lemon, zest finely grated
  • Tabasco-style sauce, to taste
  • Ice cubes or crushed ice, for serving
  • Lemon wedges, for serving (optional)