Preheat the oven to 350¼F. Grease a roasting pan with the butter. Combine the beef, pork, onions, bell peppers, garlic, eggs, cream, breadcrumbs, salt, pepper, and Essence in a large mixing bowl, and stir with a wooden spoon. Mold half of the meat into a loaf shape, about 9x4 inches, in the prepared pan. Put the sausage on top of the loaf. Mold the remaining meat mixture around and on top of the sausage to cover it completely. Pour the chili sauce on the top and bake, basting occasionally with the pan juices, for 11/2 hours. Remove from the oven and carefully transfer the meatloaf to a serving platter.
Transfer the roasting pan to the stovetop and heat over high heat. Stir in the stock and cook, stirring constantly, for 1 minute. Combine the flour and 2 tablespoon of water in a small bowl, and whisk to dissolve the flour. Add the mixture to the stock and whisk to blend. Bring to a boil and cook, stirring, until the gravy thickens slightly, about 2 minutes.
Serve the meatloaf with hot mashed potatoes and gravy.
Makes 4 to 6 servings