Steps

1. Combine the bread and milk in a small dish; let sit 15 minutes.
2. Heat a small skillet over medium heat. Add 1 tablespoon of the butter and the onion; sauté until soft but not colored, about 3 minutes. Let cool.
3. In a large bowl, whisk together the egg, salt, allspice, and pepper. Using the back of a fork, mash the soaked bread. Stir the bread and onion into the egg mixture. Add the beef and pork, and combine gently by hand. Using damp hands, shape into walnut-sized balls (you should have about 30) and refrigerate for 30 minutes.
4. Heat the oil in a 12-inch nonstick skillet over medium-high heat. Add half of the meatballs and brown on all sides, about 6 to 8 minutes. Transfer to a plate and keep warm. Repeat with the remaining meatballs.
5. Pour the fat from the pan and add the remaining tablespoon of butter and the flour. Cook until golden and nutty, about 2 minutes. Whisk in the broth and bring to a boil, scraping up browned bits from bottom of pan. Stir in the jelly and the cream; simmer until slightly thickened, about 5 minutes.
6. Return the meatballs to the pan, turning to coat. Reduce the heat to medium-low, cover, and simmer until just warmed through, about 5 minutes more. Serve with lingonberry preserves.