You'll need around 300g soft fruit to make the amount if puree needed. Peel it & stone it if necessary, then chop into pieces and whizz up in a blender

Cook the fruit puree with the sugar over a medium low heat until a syrup thick enough to coat the back of a spoon forms, like when making jam. This will take anywhere from 30 - 60 minutes

Add the butter and stir for a few minutes to get rid of any foam that's formed, then take off the heat and quickly stir in the pectin

Pour immediately into the tin and let cool at room temp, then refrigerate overnight

When fully set, cut into squares with a sharp knife dipped in hot water to aid slicing. I make 8 slices then cut each slice into 5 squares