In a small bowl, combine breadcrumbs and 1/2-cup heavy cream. Stir with fork until smooth. Set aside. In a small saute pan over medium heat, heat the oil and add the onion. Saute until softened but not browned, about 5 minutes. In a large bowl, combine beef, veal, pork, honey, cooked onions and egg. Season with salt and pepper to taste. Add the bread crumb-cream mixture to the meat, and mix well. With wet hands 9to keep the meat from sticking), shape a meatball the size of a golf ball. If the meat is too soft to shape, more bread crumbs may be added to the mixture. Continue shaping meatballs, placing on a plate brushed with water. There will be about 24 meatballs. In a large skillet over medium-high heat, melt the butter and add the meatballs. Saute, browning on all sides, until cooked through, about 7 minutes. Remove to a plate, and discard the fat from the skillet. Return skillet to heat, and add shallots, red pepper and plums. Saute until softened and lightly browned. Add chicken broth, then remaining 1/ 4 cup of heavy cream. Stir in plum sauce, and season to taste with salt and pepper. Add meatballs to sauce and simmer over medium heat, until sauce thickens slightly and meatballs are heated through, about 5 minutes. Serve.