In a medium saucepan over medium heat, combine the strawberries, 1/2 cup of water, sugar and lemon juice. Stir frequently, and bring to a low boil.
In a small bowl, whisk the cornstarch with 2 tablespoons of cold water.
Slowly stir the cornstarch into the strawberry mixture. Simmer until the homemade strawberry sauce is thick enough to coat the back of a metal spoon, about 5 minutes.
Remove from heat and gently stir in vanilla.
Serve warm or pour into an airtight container and chill in the refrigerator before serving.
Notes
Makes about 3 cups.
If using frozen berries, you do not need to thaw them before making the sauce.
You may use sliced or whole berries in this sauce. If using whole berries, you may want to use a potato masher to break the berries up as the sauce cooks.