Avocados Stuffed with Shrimp Rémoulade

Name: Avocados Stuffed with Shrimp Rémoulade
Ingredients: 1 lemon; 1 egg; 1⁄4 cup Creole mustard; 1⁄4 cup prepared horseradish; Salt; 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