Fresh strawberries are the star ingredient in this no-cook, no-churn ice cream. Instead of adding bits of fruit, which turn icy and hard when frozen, we stir berry puree into the base for a uniformly creamy texture and fresh flavor throughout. Long ago, Italians discovered that dark, sweet-tart balsamic vinegar perfectly complements the rosy notes of strawberries. No need to use a spendy traditional balsamic here; we had success with decent imported supermarket brands such as Lucini and Cento. Bittersweet chocolate is an excellent mix-in for this ice cream. Stir in about 4 ounces, finely chopped, after transferring the mixture from the food processor or stand mixer to the chilled bowl, just before the final freeze.