optional garnishes: sour cream, grated cheddar cheese, finely chopped red onion, and cilantro leaves or chives
Add the diced bacon to a large pot (a Dutch oven is perfect), and place it over medium heat. Moving it around occasionally, cook the bacon until the pieces are becoming crisp, about 5 minutes.
Stir in the onion and garlic and cook until the onions are soft and beginning to brown, about 10 minutes. (You shouldn't need to add oil to the pan -- the bacon fat should be sufficient.)
Use a slotted spoon to remove the bacon-onion mixture and place it in a bowl. Set aside.
Sprinkle the meat with salt and pepper, and turn the heat up to high. Add the meat to the pan. (You should hear a sizzling sound -- if you don't the pan isn't hot enough.) Sear the meat, browning all sides, and then return the bacon-onion mixture to the pot.
Add the oregano, cumin, chili powder and cloves and continue to cook for another couple of minutes.
Deglaze the pot with the wine and tomatoes, and use a wooden spatula to scrape any bits of food off the bottom of the out and into the mixture.
Stir in the chipotles, turn the heat to low, cover the pot, and simmer until the pieces of meat are super tender -- almost (but not quite), falling apart, 2½ to 3 hours. Stir the chili from time to time.
Mix in all of the beans and the chocolate and cook on low for about 10 more minutes.