Combine strawberries and sugar in a medium pot or saucepan.
Whisk together lemon juice, vanilla extract and cornstarch in a small bowl until fully smooth/no lumps remain. Pour over strawberries and stir well.
Bring to a boil once over medium-high heat, then reduce to medium heat and simmer sauce until berries are soft and juices have thickened slightly, about 5 minutes for a chunky topping.
Use warm, at room temperature or chilled.
