Blackberry and Blueberry Sauce

Preparation

1. Step 1

   In a medium saucepan set over medium heat, stir together the sugar, lemon juice, and half the blueberries and blackberries. Bring just to a boil. Reduce heat to low, and simmer until the blueberries burst and release their juices, about 3 minutes.

   Step 2

   In a small bowl, dissolve the cornstarch in 1 teaspoon cold water. Stir into the sauce. Simmer, stirring, about 1 minute more, until the sauce thickens slightly. Remove from the heat; stir in the remaining berries. Transfer the sauce to a serving bowl. Chill until cold; stir before serving with the pie.