Toss the pork cubes with salt and pepper; set aside.
Fry bacon in a large, heavy soup kettle or Dutch oven over medium heat until fat renders and the bacon crisps, about 10 minutes.
Remove the bacon with a slotted spoon to a plate lined with paper towels; pour all but 2 t of fat from the pot into a small bowl; set aside.
Increase heat to med-high, add half of the meat to the now empty pot, and cook until well browned on all sides, about 5 minutes.
Transfer the browned meat to a bowl.
Brown the remaining meat, adding another 2 t bacon fat to the pot if necessary; transfer the second batch of meat to the bowl.
Decrease heat to med-low and add 3 T bacon fat to the now empty pot.
Add the onion, jalapeno, chili powder, cumin, and oregano; cook, stirring occasionally until the vegetables are beginning to brown, 4-5 minutes.
Add the garlic and brown sugar; cook until just fragrant, about 15 seconds.
Add the diced tomatoes and scrape the pot bottom to loosen any browned bits.
Add the reserved bacon, browned pork, and water; bring to a simmer.
Continue to cook, uncovered, at a slow simmer until the meat is tender and the juices are dark and starting to thicken, about 2 hours.
Add the beans, reduce heat to low, and simmer, uncovered, stirring occasionally, for 30 minutes.
Adjust the seasoning with additional salt if necessary and serve with desired toppings-diced fresh tomatoes, lime wedges, diced avocado, sliced scallions, chopped red onion, chopped cilantro, sour cream, shredded Monterey Jack cheese or cheddar.