Grilled Amberjack Sandwiches with Spicy Tartar Sauce

Name: Grilled Amberjack Sandwiches with Spicy Tartar Sauce
Ingredients: Four 4- to 6-ounce amberjack fillets, cleaned of all skin and bones (mahi does well as a substitute); 2 tablespoons olive oil; 2 teaspoons fish rub, such as Emeril's Fish Rub; 1 cup mayonnaise, homemade or store-bought; 2 tablespoons minced fresh cilantro or dill; 2 tablespoons dill pickle relish; 2 teaspoons minced garlic; Sea salt and cracked black pepper; 1 to 2 tablespoons hot sauce of choice, preferably Louisiana-style or Sriracha; 4 medium hamburger buns or rolls of choice; 4 large leaves romaine lettuce