FOR THE MEATBALLS: Mix all meatball ingredients together, using your hands.
NOTE: Do not taste this mixture because it contains raw pork; also be sure to wash you hands well in hot soapy water when you have finished working with the meat mixture.
Cover mixture and chill 2 to 3 hours until firm enough to shape easily. Roll into balls about the size of golf balls, arrange in one layer on a large tray, cover and chill 1 to 2 hours.
TO POACH: Bring beef broth and water to a simmer in a large heavy saucepan over moderate heat Drop half the meatballs into the liquid, and when it returns to a slow simmer, adjust burner heat as need so that it ripples steadily but gently. Poach the meatballs uncovered for 20 minutes; remove to a heatproof bowl, using a slotted spoon, cover loosely with foil and keep warm. Poach the balance of the meatballs the same way and transfer to the bowl with a slotted spoon. Re-cover with foil and keep warm.
FOR THE SAUCE: Boil poaching liquid hard until it has reduced to 2 cups—about 20 minutes. Meanwhile, melt the butter in a small heavy saucepan over moderately low heat; add shallots and stir fry about 5 minutes until limp and golden but not brown. Blend in flour and mellow 2 to 3 minutes over low heat. When poaching liquid has reduced sufficiently, whisk about half of it into the flour paste, stir this mixture back into pan of poaching liquid and cook, stirring constantly, until thickened and smooth—about 3 minutes. Stir in the capers, then return all meatballs to pan and warm them very slowly in the sauce for 10 to 15 minutes with the kettle lid set on askew.
NOTE: If you turn burner heat to lowest point, you can hold the meatballs at this point for nearly an hour; just make certain that the sauce does not boil. (Use a flame tamer underneath the saucepan.) And if the sauce should thicken too much, thin with a little water.
When ready to serve, smooth the sour cream into the sauce and warm, stirring ever so gently so as not to damage the fragile meatballs, for about 5 minutes longer. Serve with boiled new potatoes an assertive green vegetable such as Brussels sprouts or broccoli.
Serves 4 to 6.
Jean Anderson Cooks.