Chicken, melon, walnuts and feta top mixed salad greens for a refreshing summer salad. Use your favorite summer fruit in place of the melon if you wish.
Whisk sour cream, vinegar, sugar, poppy seeds, salt and pepper in a large bowl until smooth. Reserve 1/4 cup of the dressing in a small bowl. Add the mixed greens to the large bowl and toss to coat. Divide among 4 plates and top with chicken, melon, walnuts and feta. Drizzle each portion with 1 tablespoon of the reserved dressing.
Tips: To poach chicken breast: Place boneless, skinless chicken breasts in a medium skillet or saucepan and add lightly salted water to cover; bring to a boil. Cover, reduce heat to low and simmer gently until chicken is cooked through and no longer pink in the middle, 10 to 12 minutes. To toast chopped or sliced nuts, heat a small dry skillet over medium-low heat. Add nuts and cook, stirring, until lightly browned and fragrant, 2 to 3 minutes.