Render out the oil from the bacon, remove and reserve the bacon.
Thoroughly salt and pepper the ribs, brown them on all sides, over med-high heat.
Turn down the heat to a low/simmer, and add the onion and a pinch of salt; saute for 5 minutes or so, until onion soft and translucent.
Add garlic, saute for about 30 seconds -- don't overcook or brown.
Add (2 tbsp) all-purpose flour, cook for 2 minutes to make a roux.
Add 1 cup of dry sherry, stir it in and deglaze the bottom, bring that up to a simmer and add the bacon, browned short ribs (bone side up), 1 qt. beef stock (mostly cover them), bay leaves, thyme -- everything but chocolate and cinnamon.
Simmer for 1.5 hours, covered, start counting when you just start seeing bubbles.
Add the chocolate (broken up in small pieces) and cinnamon, stir until chocolate melts.
Put the lid back on, let it go for 30 more minutes.
Let it cool; put it in the fridge overnight.
Next day, while it's still cold, scoop the fat off of the top.
Heat everything for 15 to 20 minutes over a low heat.
Remove the ribs.
Add a little bit more dark chocolate and a dash more cinnamon, and simmer the sauce until its volume reduces by about half.
Restore the ribs to the reduced sauce, and serve them with the sauce once they're rewarmed to your satisfaction.
Warning: to make this properly, the you need two steps with an overnight pause between them: