Place all sauce ingredients in a dutch oven, bring to a boil, reduce heat and simmer for 30 minutes. In a large bowl, combine the ground beef, bread crumbs and pepper. In a small bowl, combine horseradish, eggs, pepper flakes and onion. Mix well and add to the meat mixture. Roll the meat mixture into bite-size balls (approximately the size of marbles). Brown the meatballs in small batches in a frying pan with a small amount of oil.
Preheat oven to 250 degrees. Drain the meatballs and transfer to the dutch oven containing the sauce. Simmer over low heat for 15 minutes. Remove to oven and bake for two hours. 300 meatballs.
To freeze, simmer the meatballs in the sauce on the stove-top (do not bake in oven) for one hour. Divide into plastic freezer bags and freeze. To reheat, place in large saucepan and heat for one hour on low. Note - the onion for the meatball mixture must be finely chopped or it tends to break away from the meat during the cooking process.