Cut 1/2 lb smoked side bacon into lardons and fry until the bacon is crispy over medium heat in a deep pot with a lid. Remove bacon and reserve.
Cut 3 lbs chuck roast into 1-2" cubes, pat dry with a paper towel and season well with kosher salt and freshly ground black pepper.
Transfer seasoned beef to the pot with the bacon drippings, increase heat to medium high. Do not crowd beef, sear only as many pieces at a time as you can fit in one layer. Sear each side until browned, about 2-3 minutes per side.
Remove seared beef to a plate and repeat with the next batch.
Add 1 medium onion, chopped to the fat remaining in the pan and stir to combine. Cook until the onions begin to brown.
Add 1 whole green bell pepper diced and 3 cloves garlic, finely chopped and cook until the garlic is frangrant about 1 minute.
Add 1 tbsp ground cumin, 1 tbsp Mexican oregano, 1 tbsp ground ancho chili powder and 1 tsp chili powder to onion mixture. Stir to combine and cook for a minute or two, or until the spices are fragrant.
Return seared beef to the pan, stir to combine with onions and spices and add 4 cups beef broth, or just enough to barely cover and add 1 14 oz can, crushed tomatoes. Stir to combine, bring to a boil, then turn down heat to a simmer and cook for 2-3 hours, or until the beef is very tender.
