In a dry skillet over medium heat, toast the peppers until fragrant and just beginning to smoke. Don’t let them burn. Transfer them to 1 medium bowl.
Bring 2 cups of the beef stock up to a boil, either stovetop or microwave is fine. Pour the hot liquid over the peppers. Steep the peppers for at least 20 minutes, but 30 minutes is better.
While the peppers are rehydrating, heat a stockpot (braiser or Dutch oven) over medium heat. Once hot, add the bacon and cook until all the fat is rendered and the bacon is crispy.
Remove the bacon with a slotted spoon to a paper-towel lined plate. Set aside. Drain and reserve the grease.
Season the beef chunks with salt and pepper.
Add about 1 tablespoon of the bacon grease back to the stockpot. Maintaining the medium heat, add the beef in batches (and not crowding them) brown the beef on all sides. Remove the browned pieces to a bowl as each batch is browned. (I know it takes a lot of time to babysit the beef to brown on all sides, but get at least 2 sides nicely seared. Those seared sides add a lot of flavor.)
Once all the beef has been browned and removed to the bowl, add the onion to the stockpot, stirring often until softened and beginning to brown. Turn the heat down if necessary to keep the onion from burning.
Add the garlic and stir for 20 seconds. Add the tomato paste, cumin, oregano, smoked paprika, allspice, chipotle powder.
Add the remaining 1 cup of stock to the pot and stir well. Turn the heat down to low while you give the chile peppers some attention.
Add the soaked peppers and their liquid into a blender. Secure the lid in place and puree the peppers.
Add the puree and the bacon to the pot. Stir well. (Note: if there is still a lot of residual puree on the inside of the blender, pour about ¼ to ½ cup of stock or water into the blender and swirl it around to loosen it, then add to the pot. You don’t want to waste any of that awesome flavor!)
Bring the chile mixture up to a gentle boil over medium-low heat, taste for seasoning, and adjust as needed.
Add the beef and any liquid in the bowl back to the sauce mixture. Stir well.
Place the lid on the pot. Lower the heat to a low, gentle simmer. Cook for 1 hour. Stir. Place the lid back on the pot. (You will notice the beef seems “tough.” That’s the nature of cooking beef; it will go through stages of collagen tightening before it relaxes into a tender, mouthful of yumm.)
Sprinkle the masa flour, 1 tablespoon at a time, and stir. You may not use all 4 tablespoons if you are content with the thickness of the chili at 2 or 3 tablespoons. Continue to cook for another 30 minutes on low, uncovered, or until the chunks of beef are very tender.
Remove and discard the bay leaf. Taste and adjust any seasonings as desired.
Serve very warm with preferred toppings.