Remove from heat and let cool. Serve warm or chilled. Refrigerate chutney in an airtight container up to a week.
To prepare meatballs: In a large bowl, use hands to mix together pork, beef, onion, sour cream, egg, breadcrumbs, salt, pepper, allspice, and nutmeg until well combined. Shape into 23 (1 3⁄4-in.) balls. Reserve one meatball to use in sauce. Place remaining meatballs on a foil-lined, rimmed baking sheet and freeze 20 to 30 minutes. Remove from freezer and reroll each meatball in hands to make round again, if needed.
Preheat oven to 350 degrees. Bake meatballs until browned and cooked through, about 30 minutes.
While meatballs are cooking, prepare noodles according to package directions. When meatballs are almost finished cooking, whisk together the broth and cornstarch in a medium bowl and set aside.
Heat oil in a medium saucepan over medium heat. Add reserved meatball and break up into small pieces. Cook, stirring occasionally, until pieces are deep brown. Add the vinegar and deglaze the pan by scraping up browned bits. Cook until vinegar is almost evaporated. Whisk in reserved broth and cornstarch mixture. Bring to a simmer and stir until thickened, 3 to 4 minutes. Season with salt and pepper, to taste.
In a large bowl, toss cooked noodles with melted butter and caraway seeds. Serve noodles topped with meatballs, sauce, and plenty of chopped parsley. Serve with cranberry chutney.