4 (6-ounce) skin-on or skinless salmon fillets, pin bones removed (24 ounces total)
1 tablespoon, plus 1 to 2 teaspoons white-wine vinegar, divided
1 teaspoon salt, plus more to taste
1 cup low-fat or regular sour cream (do not use nonfat)
1 cup 1/4-inch diced cantaloupe
1 to 2 teaspoons sugar
1 tablespoon finely chopped mint leaves, plus small sprigs for garnish
Freshly ground black pepper, to taste

Have ready a pot large enough to hold the salmon pieces without crowding. Fill it with enough water to cover pieces by 2 to 3 inches. Add 1 tablespoon of the vinegar and the 1 teaspoon salt. Bring water to a boil over medium-high heat, then add salmon pieces. Reduce heat to medium or medium-low so poaching water just barely bubbles. Cook, uncovered, to desired degree of doneness; 1/2-inch-thick fillets will be done in 7 to 8 minutes. Use a slotted spatula to transfer to a plate; if using skin-on fillets, discard skin at this point.

While salmon is cooking, make sauce. Combine the sour cream, cantaloupe, 1 teaspoon of the sugar, 1 teaspoon of the vinegar, the chopped mint and salt and pepper, to taste. Taste and add sugar and/or vinegar, as necessary.

Divide salmon fillets among individual plates. Spoon melon-mint sauce over each portion. Garnish with the mint sprigs; serve chilled or at room temperature. May be made several hours ahead.

Makes 4 servings.