Ingredients

1 large egg
1 fresh lemon (about 2 tablespoons)
1/4 cup chopped onions
1/4 cup chopped green onions
1/4 cup chopped celery
1 tablespoon prepared horseradish
3 tablespoons Creole or whole-grain mustard
3 tablespoons prepared yellow mustard
3 tablespoons ketchup
3 tablespoons chopped parsley
Salt
Cayenne pepper
Freshly ground black pepper
1 cup vegetable oil

Directions

Combine the first 10 ingredients in a food processor with a

metal blade and process until smooth. Season with salt, cayenne, and pepper. While the machine is running,
slowly add the oil, a little at a time, until the thick. Reseason if needed. Cover and refrigerate for at
least 1 hour before serving. Can be stored for up to 1 week.