Dice the onion.
Mix the ground pork and ground beef together.
Season the mix with salt & pepper to taste, plus the nutmeg and Allspice.
Add the diced onions.
Combine the milk and the breadcrumbs, and then add this to the meat.
Mix all of the ingredients thoroughly, then separate into 8 equal parts and roll into fat sausages.
Wrap each of the sausages tightly with a slice of bacon. Roll them on the counter or cutting board with the palm of your hand to make them secure.
Cover and refrigerate for at least an hour.
If you would like to freeze them, after chilling you can wrap them individually in wax paper and then put them in a freezer bag.
Once the sausages have sat and chilled, remove them from the fridge (or if frozen, allow to thoroughly thaw and come to room temp.
Preheat your oven to 300 degrees F.
Melt the butter in a skillet over medium low heat and then slowly brown each of the wrapped sausages, ~3 minutes on each side.
Once browned, put the Slavinken in a baking dish and continue cooking in the oven until they reach 145 degrees F internally.