Place the clean dry berries in a deep medium saucepan. Add the lemon juice, sugar and salt. Bring to a boil over medium heat. Once the sauce boils, mash some of the berries with a fork but be sure to leave some whole for good texture.  Slowly stir in about half of the cornstarch and water mixture, while stirring constantly. Add more of the cornstarch mixture if needed or until the sauce is as thick as you want.  Remove the pan from the heat and stir in the vanilla. Serve immediately and refrigerate leftovers.  Easy peasy.