Unlike the French sauce of the same name, Louisiana rémoulade is a spicy vinaigrette flavored with pungent Creole mustard.
1⁄4 cup Creole mustard
1⁄4 cup prepared horseradish
1 tsp. paprika
1 cup olive oil
1⁄4 cup white vinegar
2 cloves garlic, peeled and minced
2 sprigs parsley, leaves chopped
1 small rib celery, trimmed and chopped
1 shallot, peeled and finely chopped
1 bay leaf
2 tsp. worcestershire sauce
2–3 dashes Tabasco
1 lb. medium shrimp, peeled and deveined
8 leaves romaine lettuce
4 small haas avocados, halved, seeded, and peeled
1. Using a paring knife, trim rind off lemon in wide strips, then cut lemon in half and squeeze juice into a small bowl. Set rind and juice aside. Whisk together egg, mustard, horseradish, 1 tsp. salt, and paprika in a medium mixing bowl. Gradually add oil in a slow, steady stream, while whisking constantly, until oil is incorporated and mixture is emulsified. Stir in vinegar, garlic, parsley, celery, shallots, bay leaf, worcestershire, and the reserved lemon rind and juice. Add Tabasco to taste, cover with plastic wrap, and refrigerate rémoulade for at least 6 hours or overnight. Remove and discard lemon rind and bay leaf.
2. Bring a medium pot of salted water to a boil over high heat. Add shrimp and cook until they begin to float and are just cooked through, 3–5 minutes. Drain, then plunge into a large bowl of ice water to chill, and drain again. Add shrimp to rémoulade.
3. Divide romaine leaves among eight chilled salad plates, then rest an avocado half, cut side up, on lettuce, and spoon shrimp and rémoulade over each. Serve with sliced French bread, if you like.