Juicy and Tender Swedish Meatballs With Rich Gravy Recipe

Name: Juicy and Tender Swedish Meatballs With Rich Gravy Recipe
Ingredients: 3 ounces (80g) fresh white bread, crusts removed, bread cut into 1/2-inch pieces (about 1 3/4 unpacked cups); 1/2 cup (120ml) milk; 5 tablespoons (75g) unsalted butter, divided; 1 medium onion, minced or grated, divided (see note); 1 pound 4 ounces (560g) ground beef chuck (about 20% fat); 12 ounces (340g) ground pork (about 25% fat); 4 teaspoons (18g) kosher salt, plus more for seasoning; 2 large eggs; 1/4 teaspoon ground white pepper, plus more for seasoning; 1/8 teaspoon ground allspice; Canola or vegetable oil, for frying; 3 tablespoons (45g) flour; 2 cups (480ml) homemade chicken stock or store-bought or store-bought low-sodium chicken broth; 1 teaspoon (5ml) soy sauce; 1/2 teaspoon apple cider vinegar; Minced flat-leaf parsley, to garnish; Buttered boiled Yukon Gold potatoes and lingonberry jam, for serving (optional)