2-pounds langoustines. To clean pull off the claws and legs. Make a slit down the center splitting the shell in half. Remove the vain. Steam the langoustines in water, lemon juice, 1 whole garlic pod, and a 1/2 teaspoon liquid crab boil until they turn orange. Remove from the heat, put in an ice bath to stop the cooking. Reserve one to put on the rim of each serving glass.
½ cup mayonnaise., ½ cup catsup, ½ cup prepared creamy horseradish, 1 tablespoon Worcestershire sauce, ½ teaspoon salt, 2 ¼ tablespoons fresh lime juice, ½ cup cilantro, finely chopped, ¼ cup jicama, finely chopped, 1 teaspoon hot sauce, flat leaf parsley and lemon slices for decoration.
In a glass bowl stir together all the ingredients. Pour the sauce over shrimp then spoon the cocktail sauce into a martini glass. Garnish with one langoustine, a lemon wedge and a couple of pieces of parsley and fresh rosemary.