Toast walnuts on a baking sheet in a 350 degree F oven for 8 to 10 minutes. Remove from oven; set aside. Simmer wine for 5 minutes in a small saucepan; set aside to cool.
Cook and stir half-and-half or light cream, sugar, and vanilla in medium saucepan over medium heat until sugar is dissolved. Stir 1/2 cup of half-and-half mixture into beaten egg yolks. Return mixture to saucepan. Cook and stir over low heat until mixture thickens. Remove from heat; allow to cool. Stir in whipping cream, cooled wine, and toasted walnuts. Refrigerate 30 minutes or until well chilled.
Freeze the mixture in an ice-cream machine according to manufacturers directions. Makes 2 quarts.