Combine the breadcrumbs and heavy cream in a small bowl, stirring with a fork until all the crumbs are moistened. Set aside. Heat the oil in a small skillet over medium heat. Add the onion and sauté for about five minutes, until softened. Remove from heat. In a large bowl, combine the ground beef, veal, pork, onion, honey and egg, and mix well with your hands. Season with salt and pepper to taste. Add the breadcrumb-cream mixture and mix well. With wet hands (to keep the mixture from sticking), shape the mixture into meatballs the size of a golf ball, placing them on a plate lightly moistened with water. You should have about 24 meatballs. Melt the butter in a large skillet over medium-high heat. Add the meatballs, in batches if necessary, and cook, turning frequently, for about 7 minutes until browned on all sides and cooked through. Transfer the meatballs to a plate and drain off all but 1 tablespoon of fat from the skillet. Return the skillet to the heat, whisk in the stock, cream, preserves and pickle juice, and bring to a simmer. Season to taste with salt and pepper. Add the meatballs to the sauce, reduce the heat to medium and simmer for about five minutes, until the sauce thickens slightly and the meatballs are heated through. Serve hot with mashed potatoes and quick-pickled cucumbers.