To make the rissoles, all you do is place the onion, breadcrumbs, apple, sage, mace, salt and some fresh milled black pepper into the bowl of a processor and blend everything on a low speed, then add the pork and blend again until everything is thoroughy mixed.
If you don't have a processor, grate the onion and apple and mix the ingredients together with a fork. Now divide the the mixture into 16 and shape into rounds so you end up with 16 rissoles. All this can be done in advance, and the rissoles can be covered and chilled in the fridge.
Meanwhile, to make the sauce, soften the onion in the butter for 8-10 minutes, then stir in the chopped apple and 1 tablespoon water. Put a lid on and simmer for 8-10 minutes or until the apple is soft, then add a little freshly grated nutmeg, a couple of small pinches of ground cloves and the sugar. Beat the sauce till fluffy and taste to see it is needs a little more sugar.
When you're ready to cook, heat some oil in a frying-pan (just enough to cover the base) and when it's very hot, fry the rissoles in two batches for about 5 minutes on each side (if you're using raw pork, they will need 6-7 minutes). Serve the spiced apple sauce hot with the rissoles.