In a large Dutch oven or heavy-bottomed pot, cook the bacon over medium heat until crispy; remove bacon and set aside, reserving the rendered fat in the pot. Sear the beef cubes in batches until browned on all sides, then remove the beef and set it aside.

Add the chopped onion to the pot and cook until softened, about 5-7 minutes; stir in the minced garlic and cook for another minute until fragrant. Return the browned beef to the pot, then stir in the beef broth, tomato paste, chili powder, and any other desired seasonings.

Bring the chili to a simmer, then reduce heat to low, cover, and cook for at least 2 hours, or until the beef is very tender. Stir occasionally to prevent sticking and add more broth as needed to maintain desired consistency. Serve hot, garnished with crumbled bacon and any other preferred toppings.