1 large yellow or white onion, peeled, grated (through a cheese grater)
2 Tbsp butter
2/3 cup milk
4-5 slices of bread, crusts removed, bread cut into pieces
1 pound ground pork
1 1/2 pounds ground beef
2 teaspoons salt
1 teaspoon freshly ground nutmeg
1 teaspoon ground cardamom
2 teaspoons black pepper
6 Tbsp butter
1/3 cup flour
1 quart beef stock
1/2 to 3/4 cup sour cream
2 to 4 Tbsp of Lingonberry, cranberry, red currant or raspberry jelly, more or less to taste (optional)
Saut? the grated onion in the butter over medium-high heat until the onions soften and turn translucent, about 3-4 minutes. Remove from heat and let cool.
In a medium bowl, mix the bread pieces with the milk. Set aside for 15-20 minutes, or until the bread soaks up all the milk. When it does, pulverize the bread in a food processor and pour it into a large bowl.
Add the cooled onions to the bowl of milk and bread. Add the rest of the meatball ingredients?eggs, ground pork, ground beef, salt, nutmeg, cardamom, pepper. Using your (clean) hands, mix well for about 2 minutes until the ingredients are well combined.
Use a tablespoon to measure out the meat for the meatballs. As you form the meatballs, set each one aside on a sheet pan or plate. You should get 40 to 50 meatballs.
Heat 6 tablespoons of butter for the sauce in a large saut? pan over medium heat. When the butter has melted, reduce the heat to medium and add some of the meatballs. Do not crowd the pan. Work in batches, browning them slowly on all sides. Be gentle when you turn them so they don’t break apart. Do not cook the meatballs all the way through, only brown them at this stage. Once browned, use a slotted spoon to remove them from the pan, setting them aside so you can make the sauce with the remaining pan butter.
Start the sauce. (Check the pan butter to see if it has burned. If the butter tastes burnt, discard the butter and replace with new 6 tablespoons.) Heat the pan butter on medium until hot. Slowly whisk in the flour. Stirring often, let the flour cook until it is the color of coffee-with-cream; this is a classic roux.
As the roux is cooking, heat the beef stock in another pot until it simmers. When the roux has cooked until the color of coffee-with-cream, slowly add the hot beef stock a little at a time. Everything will sputter at first, and the sauce will seize up and solidify. Keep stirring and adding stock slowly, and it will loosen up and become silky.
Add the meatballs to the sauce and turn the heat down to low. Cover the pot and cook on low heat for 10 minutes. You might need to do this in batches.
To finish, move the meatballs to a serving dish. Add the sour cream and mix well. Either add the lingonberry jelly to the sauce or serve it on the side.