1. Preheat oven to 325 degrees.
2. Combine 1/4 cup milk and white chocolate in a small bowl. Combine 1-1/4 cups milk, sugar, and salt in a medium saucepan over medium heat; cook until sugar dissolves, stirring as needed to dissolve sugar evenly (about 3 minutes).
3. Combine egg white and eggs in a bowl, stirring well with a whisk. Gradually add hot milk mixture to eggs, stirring constantly with a whisk. Stir in white-chocolate mixture and vanilla. Remove from heat. Pour into 6 (4-ounce) ramekins. Place ramekins in a 13 x 9-inch baking pan; add hot water to pan to a depth of 1 inch. Bake at 325 degrees for 25 minutes or until a knife inserted in center comes out clean. Remove from pan; cool completely on a wire rack. Top custards with berries.