Grandma's Authentic Swedish Meatballs

Mix beef, sausage, bread crumbs, onion, milk, egg, parsley, salt, Worcestershire sauce, and pepper in a large bowl. Form into meatballs.

Heat oil in a skillet over medium-high heat. Pan-fry meatballs in batches, turning as needed, until browned and heated through, 6 to 8 minutes.

Mix boiling water, sour cream, flour, paprika, and pepper together in a deep saucepan over low heat. Add the meatballs and let simmer until thickened and heated through, 15 to 20 minutes.