In a small bowl whisk together mayonnaise, mustard, lemon juice, garlic, salt, and pepper. Add salmon to a large bowl along with the whisked mayonnaise mixture, finely chopped chives and dill, and the breadcrumbs. Mix by hand until all ingredients are well incorporated.
¼ cup mayonnaise, 1 teaspoon mustard, 1 tablespoon lemon juice, 2 cloves garlic, 1 teaspoon salt, ¼ teaspoon black pepper, 2 tablespoons finely chopped fresh chives, 1 tablespoon finely chopped fresh dill, ¼ cup Panko breadcrumbs