Wash and clean the strawberries, cut into pieces and finely puree in a blender (thaw frozen strawberries and puree).
Pluck the basil leaves and chop finely. Put the strawberry puree with the juice of the lime and the preserving sugar in a saucepan. Bring to the boil and simmer for 4 minutes. Stir it again and again.
Take the saucepan off the heat and stir in the basil. Pour the mixture into a mason jar and let it cool.
Tastes good on brioche or white bread coated with mascarpone. You can sprinkle pine nuts over the top if you like.