Why use frozen berries in the summer, when local fruit is at its peak? Because we love fresh local berries so much when whole or, in the case of strawberries, when sliced as well, puréeing them seems almost a sacrilege. If, however, you've got a surplus of fresh berries, go ahead and purée them.
Cooks' note:
•Sauce can be made 3 days ahead and chilled, covered. Bring to room temperature to serve.
