In a large skillet, over medium heat, warm the oil. Add onions and cook, stirring occasionally, until tender, about 20 minutes. Meanwhile in a 4 to 5 qt. heavy flameproof casserole or Dutch oven over medium heat, combine beef and pork. Season with 2 T salt and cook, stirring often, until meat has lost all its pink color and is evenly crumbled, about 20 minutes. Scrape onions into casserole with meats. Stir in chili powder, cumin, oregano, cocoa, cinnamon and cayenne pepper. Cook, stirring, 5 minutes. Stir in tomato juice and beef stock. Bring to a boil then lower heat and simmer, uncovered, for 1 hour. Taste, correct seasonings and simmer another 30 minutes or until chili is thickened to your liking. Stir in garlic. To thicken chili further or to bind any surface fats, stir in the optional cornmeal. Stir in the beans and simmer another 5 minutes. Serves 6 or more.