Place all of the ingredients for the meatballs in a large mixing bowl and knead it together really well to form a pasty, uniform mixture. Form into meatballs, about an inch in diameter or larger if you prefer. (These can be made in advance and covered and refrigerated until ready to cook.)
Place the beef broth, onion, bay leaves, cloves and peppercorns in a medium-sized pot and bring it to a boil. Reduce the heat and carefully lower the meatballs in the broth. Return the meatballs to a very low simmer, never boiling, cover the pot, and let them gently cook for 20 minutes. Transfer the meatballs to a plate and tent with foil to keep warm. Pour the broth through a fine-meshed strainer and reserve 1 1/2 cups of the strained cooking broth.
To make the lemon caper cream sauce: Melt the butter in a medium-sized saucepan over medium heat. Add the flour and use a wire whisk to blend it with the butter. Let the mixture bubble for one minute, continually whisking. Gradually add the reserved cooking broth while continually whisking to prevent lumps and continue to whisk until smooth. Add the heavy cream, white wine, capers, salt, pepper and sugar, and simmer for a couple of minutes until thickened. Add the lemon juice a little at a time, adding more as desired. Add more salt, pepper, and sugar to taste. Turn off the heat and whisk in the egg yolk. Place the meatballs in the sauce to coat.
Serve the meatballs and sauce garnished with chopped parsley or chives. Serve with salted boiled potatoes (preferably a firm, yellow variety such as Yukon Gold) and pickled beets (the traditional sides of choice).