Salmon Burgers with Yogurt-Dill Sauce

Heat broiler, with rack set 4 inches from heat. In a medium bowl, combine salmon, horseradish, lemon zest and juice, egg, scallions, breadcrumbs, 1 teaspoon salt, and 1/8 teaspoon pepper; mix gently with a fork.

Form salmon mixture into four 3 1/2-by-1-inch patties; place on a rimmed baking sheet. Broil without turning until browned on top and opaque throughout, 6 to 7 minutes.

Meanwhile, combine yogurt and dill in a small bowl; season with salt and pepper. Serve burgers on buns with yogurt-dill sauce and lettuce.