My own version of Swedish Meatballs. I took them to a potluck and they promptly disappeared!
Caramelize 1/2 of an onion in olive oil. In large bowl, mix 2 lb. ground beef, 1/2 lb. ground sausage, 1/2 Cup Panko bread crumbs, 2 eggs, 1/2 tsp. nutmeg, 1 tsp. cardamom, 1/2 tsp. garlic powder, 1 tsp. kosher salt and some fresh
ground pepper to taste. Roll this mixture into small balls and brown on all sides in 6 Tbsp. butter. Set aside. In a large saucepan, melt 6 Tbsp. butter and whisk in 1/3 Cup flour. To this add 4 Cups beef broth and 1 Tbsp. Worcestershire sauce. Place the meatballs in sauce and cook on medium heat covered for about 8 minutes. Stir in 3/4 Cup sour cream and 1 tsp. Dijon mustard. Serve over rice or noodles!