Preparing the sauce
In a large bowl, mix together all of the meatball ingredients and roll into balls 1 inch (2 cm) in diameter. Set aside.
Soak the shanks in brine for 3 hours before placing them in a large pot of simmering pork stock. Simmer for 3 hours, until the meat comes off the bone without falling into pieces. Set the shanks aside.
Reduce the broth by half to concentrate the flavour. Set aside.
Do not reduce the broth too much or it will become too salty from the brining of the shanks.
In a large skillet, heat the lard and add the meatballs, browning until nicely golden. Transfer them to the pot of simmering broth and cook for 5 minutes. Remove and set aside.
Add the onions and the potatoes to the broth and cook them until tender. Remove from the broth and set aside.
Preheat the oven to 400?F (200?C). Sprinkle the flour on a baking tray and place in the oven. Stir the flour every 5 minutes so that it roasts evenly. Roast the flour until dark brown. Set aside.
Bring the broth to a boil.
Sprinkle in the roasted flour and mix briskly with a whisk.
Cook over medium heat for 10 minutes to thicken the sauce.
Reheat all of the ingredients in the sauce. Slowly mix in the butter thoroughly.
Serve the stew with marinated beets and pickles.