In a large bowl of a slow cooker, combine mushrooms, thyme, salt and pepper. Stir in broth.

In a large bowl, whisk the eggs with the Worcestershire, mustard, nutmeg, allspice, salt and pepper. Add in the onion, bread crumbs, turkey and pork. Mix well and roll into 1 inch balls. Place the meatballs on top of the mushrooms.

Cover and cook on low for 6-8 hours making sure meatballs come to 160F. Skim off fat. Remove some of the meatball to a plate and push others aside. Whisk sour cream with flour and add to the slow cooker, whisking in. Adjust seasoning if needed. Add the meatballs back to the slow cooker and gently mix. Cover and cook on high for 10 min. or until slightly thickened and bubbly. Serve over hot noodles.