Make meatballs: Combine ground beef, pork, onion, panko, egg, jam, allspice, 2 tablespoons of the herbs, 1 teaspoon of the salt, and ¼ teaspoon of the pepper in a medium bowl. Mix with a fork or hands until combined; roll into 20 small meatballs (2 tablespoons each), and place meatballs on a baking sheet.

Cook meatballs: Heat olive oil in large nonstick skillet over medium-high. Add meatballs, and cook, turning often, until browned on all sides and cooked through and a thermometer inserted in thickest portion registers 165°F, 8 to 10 minutes. Transfer meatballs to a plate with tongs or a slotted spoon, and cover with aluminum foil to keep warm; reserve drippings in skillet.

Make sauce: Add flour to drippings in skillet, and cook over medium, whisking constantly, until lightly browned, 1 to 2 minutes. Slowly whisk in beef broth, cream, Worcestershire sauce, vinegar, Dijon mustard, and remaining ¼ teaspoon each salt and pepper. Bring to a simmer over medium, and cook, whisking often, until sauce begins to thicken, about 3 minutes.

Add meatballs to sauce: Reduce heat to medium-low; whisk in sour cream and remaining 2 tablespoons herbs. Return cooked meatballs to skillet, and simmer, stirring occasionally, until coated, about 1 minute. Serve over cooked egg noodles; garnish with additional herbs, and serve with additional jam, if desired.