1/3 cup sugar
1/2 cup orange juice (apple juice works great too)
1 tablespoon cornstarch
2 teaspoons lemon juice
While the berries heat, blend the cornstarch into the remaining orange juice, using the back of a spoon to dissolve any lumps.
Increase the heat under the pan and bring the sauce to a boil. Stir the cornstarch mixture again and then stir it into the fruit. Cook the sauce at a low boil for 1 minute, stirring constantly.
Remove the pan from the heat and stir in the lemon juice. Cool the sauce for 5 to 10 minutes before serving (it will thicken as it cools). Makes about 2 cups.