Swedish Meatballs

Name: Swedish Meatballs
Prep time: 15 min
Total time: 15 min
Cuisine: European
Ingredients: 2 tbsp. of olive oil; 1 medium onion, chopped; 1 lb. of lean ground beef; ½ lb. of lean ground pork; ½ cup of breadcrumbs or Panko; 2 egg yolks; ¼ tsp. of ground allspice; ¼ tsp. of ground nutmeg; ½ tsp. of Kosher salt; ½ tsp. of ground black pepper; ¼ cup of butter, margarine or butter substitute; ½ cup of flour; 4 cups of beef stock; ½ cup of nonfat yogurt or cottage cheese; A pinch of kosher salt and ground black pepper to taste; 2 tbsp. of chopped fresh parsley leaves