Shrimp Rémoulade

Mince the celery, scallions, parsley, and onions in a food processor. Add the ketchup, tomato purée, Creole mustard, horseradish, red wine vinegar, paprika, and Worcestershire. Begin processing again and add the oil in a slow drizzle to emulsify. Stop when the dressing is smooth. Chill for 6 to 8 hours or overnight. Correct the seasoning with additional horseradish, if desired, after the ingredients have had the opportunity to marry.

In a large mixing bowl, add the sauce to the shrimp and toss gently to coat. Divide the lettuce among 6 chilled salad plates. Divide the shrimp evenly atop the lettuce and serve.