Andouille Sausage PoBoy with Cajun Remoulade and Crab Meat

Name: Andouille Sausage Po'Boy with Cajun Remoulade and Crab Meat
Ingredients: 3/4 cup mayonnaise; 2 tablespoons whole-grain mustard; 1 tablespoon fresh lemon juice; 1 tablespoon finely chopped fresh parsley; 2 teaspoons Louisiana-style hot sauce; 2 teaspoons Worcestershire sauce; 1 1/2 teaspoons Cajun seasoning; 1 1/2 teaspoons prepared horseradish; 1/2 small shallot, minced; Kosher salt and freshly ground black pepper; 1 stick (8 tablespoons) unsalted butter, at room temperature; 4 French rolls or hoagie rolls, split; 4 andouille sausage links (about 12 ounces); 8 ounces jumbo lump crab meat, picked through; 1 teaspoon Cajun seasoning; Kosher salt; 1 large plum tomato, thinly sliced; 1/2 cup dill pickle chips (about 16 pickle slices); 1 1/2 cups shredded iceberg lettuce (about 1/4 small head)