Preheat the oven to 350 degrees.
Grease a roasting pan with the butter. Combine the beef, pork, onions, bell peppers, garlic, eggs, cream and bread crumbs in a large mixing bowl. Blend well. Season with salt and pepper. Shape the mixture into a loaf and place on the prepared pan. Pour the stock over the top and bake for about 1 to 1 1/2 hours, bating occasionally with the pan juices. Remove from the oven. Carefully transfer the meatloaf to a platter. Put the roasting pan on the stove over high heat. In a small bowl, whisk together the flour and the water. Add to the pan and whisk to blend. Cook, stirring constantly, until the mixture thickens.
Season the gravy with salt and pepper to taste. Pour over the meatloaf and serve. You can keep the meatloaf in the refrigerator for three to four days.
Make 4 to 6 large servings