Heat the oil in a large cast-iron skillet or pan over medium-high heat. Season the cubes of chuck all over with salt and pepper. Working in batches, cook the chuck, turning occasionally, for 5 to 7 minutes, until nicely browned all over. Transfer to a slow cooker. In the same pan, cook the ground sirloin, onions, and garlic for about 10 minutes, until the sirloin is cooked through and the onions are soft. Stir in the tomato paste and beer, bring to a simmer, then pour it all over the beef in the slow cooker. Add the crushed tomatoes, broth, chili powder, chipotle, cumin, bay leaves, and cinnamon, if using. Set the slow cooker to high, cover, and cook for about 5 hours, until the chuck is fork- tender. Taste and season with more salt and black pepper if necessary. Stir in the pintos and cook until heated through. Discard the bay leaves and serve with your choice of garnishes.