Add beef chunks to a large bowl, and sprinkle with flour, salt, and black pepper. Toss to combine.
Add a heavy-duty, skillet over medium-high heat and add the oil.
Once the oil is hot, add the beef into one layer, making sure to not overcrowd thee pan. Brown, turning the pieces on all sides, for about 5 minutes per batch. Remove from pot and transfer to a plate, cover with foil.
Add more oil to the pot and cook another batch of beef. Add the browned beef to the slow cooker.
Once done cooking the beef, reduce the heat to medium and add the beer to deglaze the pot. Use a wooden spoon to scrape well the bits that stuck to the bottom. Add drippings to the slow cooker.
Add the rest of the ingredients to the crockpot, except thyme and bay leaves. Stir to combine. Top with bay leaves and thyme and cover with the lid.
Cook on Low for 7-8 hours or on High for 4-5 hours.
Once the beef is fork-tender, discard the bay leaves and thyme, stir to combine. Garnish with cilantro and serve with favorite toppings.
