Sweet and sour sauce for stir fries or as a condiment on sandwiches or salads
Stew the damsons in a large preserving pan or saucepan with only the water that they have clinging to them after being washed. Stir frequently to prevent them sticking on the bottom of the pan. This should only take 20 mins to 1/2 and hour.
In stages, pour the stewed damsons into large food mill and push through - removing the stones as you go. I used my bare fingers as I found gloves stopped me from picking them out cleanly. I just rinsed my hands between times.
You should now have a large pot of damson puree to which you add the sugar and vinegar and bring to a slow simmer.
While this is brewing, roast your whole spices in a dry pan watching carefully to avoid burning. Then crush roughly in a mortar and pestle before tying securely in a piece of muslin.
Add the muslin to the damsons along with the juice of the ginger - use your hand to squeeze it firmly - you should be left with the dryish pulp which you can add to your compost.
Season with the salt and cook for an hour or so. Then remove the spices in the muslin and add the roasted sweet potato flesh.
Remove from the heat and puree preferably with a stick blender. Bring back to a simmer and then remove from the heat.
Pour into clean hot sterilised bottles or jars.