Lemon zest contributes lively flavor and aroma to the sour cream sauce. Walnuts add crunch.

In a small bowl, combine sour cream, powdered sugar, lemon zest, lemon juice and vanilla. Whisk to mix evenly. Cover and chill for several hours.

Divide grapes equally among 6 stemmed dessert glasses or bowls. Add a dollop of sauce to each dish and top with 1/2 tablespoon of chopped walnuts. Serve immediately.

• 1/2 cup fat-free sour cream
• 2 tablespoons powdered sugar
• 1/2 teaspoon lemon zest
• 1/2 teaspoon lemon juice
• 1/8 teaspoon vanilla extract
• 1 1/2 cups red seedless grapes
• 1 1/2 cups green seedless grapes
• 3 tablespoons chopped walnuts