Wash and prepare the fruit, set aside a few strawberry slices, a few raspberries and a few blueberries to add to the sauce after blending.
Heat the remaining strawberries, raspberries, blueberries, sugar and lemon juice together in a saucepan over medium-high heat.
Bring to a simmer and cook, stirring often, for 10-15 minutes or until the fruit is broken down and the sauce is slightly thickened. Blend with an immersion blender until smooth.
Add the remaining remaining fruit and simmer on low for 10 minutes, stirring occasionally. .
Pour the fruit sauce into a jar and cool completely. Store in a tightly sealed jar in the refrigerator.
Serve heated or cold, per your taste. Enjoy.