Combine all the ingredients for the curry sauce in a saucepan and stir while bringing it to the boil over low heat.
Simmer gently for 10 minutes and remove from the heat. Pour the sauce into a clean glass or ceramic bowl and leave to cool to room temperature.
Once the sauce has cooled down completely, add it to the pork and mix well, making sure every piece of pork is covered with sauce. Cover with cling wrap and refrigerate for at least 3 hours (or up to 3 days).
Remove the meat from the fridge at least 2 hours before cooking. Put the onions in a heatproof container and add the boiling water. Leave to stand vir 2-3 minutes before adding the apricots.
Thread the pork cubes, layers of onion and apricots onto wooden or metal skewers. Keep any remaining sauce to brush over the sosaties while grilling over medium coals or in a hot oven.