White Balsamic Custard Tart with Fresh Berry Topping

1 1/4 cups all purpose flour

3 tablespoons sugar

1/4 teaspoon salt

1/2 cup (1 stick) chilled unsalted butter , cut into 1/2-inch cubes

1 large egg yolk

1 tablespoon whipping cream Filling

1/2 cup whipping cream

2 tablespoons cornstarch

2 large egg s

4 large egg yolks

1 teaspoon vanilla extract

1/2 cup white balsamic vinegar

3/4 cup water

3/4 cup sugar

1/4 cup ( 1/2 stick) unsalted butter Topping

2 large strawberries, hulled, sliced

2 1/2-pint containers blueberries

1 1/2-pint container raspberries