To prepare the meatballs: Combine the breadcrumbs and 1/4 cup 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 5 minutes, until softened. Remove from the heat.
In a large bowl, combine the beef, veal, pork, onion, honey and egg, and mix well with your hands. Season with salt and pepper to taste. Add the bread crumb-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 discard all but 1 tablespoon of fat from the skillet.
To prepare the sauce: Return the skillet to the heat, whisk in the stock, 1/2 cup 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 5 minutes, until the sauce thickens slightly and the meatballs are heated through.