Place fruit and lemon juice in a food processor fitted with a metal blade and process until smooth.
Gradually add sugar syrup
and process to blend evenly. Taste for sweetness. If sorbet needs more syrup, pour in a little more and process again.
Transfer to a medium-sized metal bowl or cake pan.
Cover with cling film and place in the freezer. Allow to partially freeze (about 4 hours) - ice will form around the edge, but the centre will be mushy.
If the mixture freezes solid, let it partially thaw at room temperature before proceeding.
Return the mixture to the processor and reprocess until completely blended, smooth and fluffy, about 1 minute.
Immediately scrape the mixture into a plastic freezer container with an airtight lid and refreeze for 4 to 10 hours.
Allow to soften at room temperature for about 15 minutes before serving.