Place the pears, sugar, allspice and nutmeg in a slow cooker and give a quick stir.
Cook on high for about 2 hours or until the pears are soft/mashable – but not liquified!
Remove pears from the slow cooker and place into a blender or food processor. Add the vanilla, sage leaves and lemon juice then process/blend until you have a thick puree.
Pour into containers and store in the fridge for up to two weeks or in the freezer (3 months up to a year)