Cook. Over medium high heat begin cooking the ingredients stirring constantly until the mixture comes to a boil then reduce temperature to medium low. Continue cooking for about 20 minutes mashing the strawberries with your spoon as you stir.
Puree. Once the strawberries have softened remove pan from the heat and use an immersion blender to puree the berries. If you don’t have an immersion blender you can also mash the berries with a fork or potato masher.
Strain. Strain the strawberries through a strainer into a bowl to remove the pulp and seeds. Make sure to press down on the strawberries to get as much of the juice out as possible.
Continue cooking. Discard the leftover pulp and seeds and pour the liquid back into your saucepan. Continue cooking over medium heat for 10 more minutes, or until the sauce is thick enough that it coats the back of your spoon.
Cool and Serve. Remove sauce from heat and let cool until it reaches room temperature. If you are not serving it right away you can store in an airtight container in the refrigerator. Bring it to room temperature before serving.