Defrost strawberries if frozen or cut up strawberries if whole.
Blend your strawberries.
Place strawberries, lemon zest, lemon juice, salt, and sugar into a small saucepan and bring to a simmer over med heat.
Once bubbling, reduce the heat to medium-low and let slowly reduce until berries begin to break up and the liquid is almost gone. This can take between 40-60 minutes depending on how much liquid you have.
Occasionally stir the mixture to prevent burning. Transfer to another container and let cool before use.
Video
Notes
Using fresh or frozen strawberries is okYou can use more or less strawberries and adjust the sugar to your liking.