Mix the sugar and water in a medium saucepan and cook over medium heat until sugar dissolves, stirring frequently. Stir in the strawberries, vinegar and ¼ teaspoon pepper.
Cook for 10 minutes longer or until the mixture is of a syrupy consistency, stirring occasionally.
To serve: Spoon the strawberry mixture over scoops of vanilla ice cream in small serving bowls. Garnish with reserved strawberry slices and sprinkle with freshly ground black pepper to taste.