Add sugar and corn starch to a small pan on the stove over medium heat.
Gradually stir in the water until your mixture is smooth.
Add your choice of berries as well as the lemon juice. Bring to a boil, then reduce heat to low and simmer, uncovered. Allow fruit to reduce for around 5 minutes.
Remove from heat and mash into pieces or blend in a processor then press through a strainer to remove any unwanted bits.
Place the fruit in an airtight container in the fridge for at least an hour until fully cooled before adding to ice cream.
