The sandwich spread, inspired by traditional tartar sauce, is brightened with the addition of fresh shallots and briny capers.
1/3 cup light mayonnaise
1 1/2 tablespoons chopped capers
1 tablespoon finely chopped shallots
1 tablespoon sweet pickle relish
4 (6-ounce) halibut fillets
1/2 teaspoon salt
1/4 teaspoon freshly ground black pepper
4 (1 1/2-ounce) hamburger buns, toasted
2 halved romaine lettuce leaves
4 (1/4-inch-thick) slices tomato
How to Make It
Combine first 4 ingredients in a small bowl, stirring well.
Sprinkle fish fillets evenly with salt and freshly ground black pepper. Heat a large nonstick grill pan over medium-high heat. Coat the pan with cooking spray. Add fish fillets to the pan; sauté 4 minutes on each side or until fish flakes easily when tested with a fork or until desired degree of doneness.
Spread 1 tablespoon mayonnaise mixture over the cut side of each bun half. Line bottom half of each bun with 1 romaine lettuce leaf half and 1 tomato slice. Top each serving with 1 fillet. Place top halves of buns on sandwiches.