Ingredients

  • 1 cup cold water
  • 3 1/2 teaspoons salt, divided
  • 1 teaspoon sugar
  • 4 (6-ounce) mackerel fillets
  • Cooking spray
  • 2 cups fresh flat-leaf parsley leaves
  • 1 cup thinly sliced Vidalia or other sweet onion
  • 1 teaspoon grated orange rind
  • 1 cup orange sections (about 2 medium)
  • 3/4 cup fresh tarragon leaves
  • 2/3 cup walnuts, toasted and coarsely chopped
  • 2 tablespoons extra-virgin olive oil
  • 1 tablespoon balsamic vinegar
  • 1/2 teaspoon grated garlic

Method

  • Preheat grill to medium-high heat.
  • Combine 1 cup water, 1 tablespoon salt, and sugar in a shallow dish. Add fillets; let stand 15 minutes. Remove fillets; pat dry. Discard brine. Place fillets, skin side down, on a grill rack coated with cooking spray. Grill 10 minutes or until desired degree of doneness. (Do not turn fillets.) Keep warm.
  • Combine parsley leaves, onion slices, orange rind, orange sections, and tarragon in a bowl. Sprinkle herb mixture with 1/4 teaspoon salt; toss. Combine walnuts and remaining ingredients, stirring with a whisk until blended. Stir in remaining 1/4 teaspoon salt. Place 1 fillet on each of 4 plates; top each serving with 1 cup herb mixture. Drizzle 2 tablespoons walnut mixture over each serving.