01 - Combine breadcrumbs and milk in a large bowl and let sit for 5 minutes, allowing the mixture to absorb liquid and soften.
02 - Incorporate ground beef, ground pork, finely chopped onion, minced garlic, egg, salt, pepper, allspice, and nutmeg into the breadcrumb mixture. Gently mix until ingredients are evenly distributed without overworking.
03 - Shape the mixture into small balls, each about 1 1/4 inches in diameter, ensuring consistency for even cooking.
04 - Heat butter and vegetable oil over medium heat in a large skillet. Cook meatballs in batches, turning occasionally, until browned on all sides (approximately 8 minutes per batch). Remove cooked meatballs; set aside.
05 - In the same skillet, melt butter and whisk in flour. Cook, stirring continuously, until the mixture is pale golden (about 1 minute).
06 - Gradually pour in stock while whisking to prevent lumps. Add heavy cream, soy sauce, and Dijon mustard. Stir and simmer until sauce thickens slightly, about 5 to 7 minutes. Season to taste with salt and pepper.
07 - Return meatballs to the skillet, spoon sauce over each, and allow them to simmer gently for 5 to 10 minutes, ensuring they are fully heated through and glazed.
08 - Serve immediately with mashed potatoes, lingonberry jam, and steamed vegetables for an authentic touch.