In a large bowl, mix together the ground beef and pork. Add the diced onion, egg, breadcrumbs, heavy cream, and seasonings: salt, pepper, and allspice.

Use your hands to blend everything together until just combined. Be careful not to overwork the mixture, as this can make the meatballs tough.

Once your mixture is ready, grab a small amount and roll it into balls about the size of a golf ball. This ensures even cooking. Place them on a plate or a baking sheet as you prepare the next steps.

In a skillet over medium heat, melt the butter and oil together. When hot, add the meatballs in batches, making sure not to overcrowd the pan. Cook until browned on all sides, about 5–7 minutes. Remove them from the skillet and set aside.

In the same skillet, add the flour and whisk it into the drippings until combined. Slowly pour in the beef stock while whisking to avoid lumps. Stir in the soy sauce and cream. Let it simmer for a few minutes until it thickens slightly.

Return the meatballs to the gravy and stir gently until they are coated. Let everything simmer together for an additional 5 minutes, allowing the flavors to meld.

Now it’s time to plate! Serve the meatballs freshly coated in gravy alongside mashed potatoes and a dollop of lingonberry sauce.