Preheat your oven to 350°F (175°C). Add the diced bacon strips to a large Dutch oven set over medium-low heat. Cook the bacon, stirring occasionally, until it is browned and has released its fat, about 8-10 minutes. With a slotted spoon, remove the cooked bacon from the pot and transfer it to a small bowl, leaving the rendered fat behind.

Season the beef chuck chunks all over with kosher salt and freshly cracked black pepper. Increase the heat under the Dutch oven to medium-high. Working in batches if necessary, sear the beef on all sides in the rendered bacon fat until deeply browned, about 4-5 minutes per batch. Remove the seared beef pieces from the pot and set aside. Searing in batches prevents overcrowding, which ensures the beef browns properly.

Reduce the heat to medium. To the same pot, add the diced onion, chopped celery ribs, chopped cabbage, and chopped carrots. Saute these vegetables, stirring frequently, until slightly softened, about 3-4 minutes. Add the minced garlic and cook for an additional minute until fragrant. Stir in the tomato paste and cook for 2-3 minutes, stirring continuously, until the tomato paste darkens in color. Sprinkle the flour over the vegetables and stir well to coat everything evenly—this will help to thicken the finished stew.

Pour in the Guinness stout, scraping the bottom of the pot with a silicone spoon or spatula to lift up any flavorful browned bits. Add the beef stock and brewed coffee, then stir to combine. Return the seared beef (from Step 2) and rendered bacon (from Step 1) to the pot. Add in the halved baby golden potatoes, thyme sprigs, and bay leaves. Stir everything together and bring the mixture up to a gentle simmer. I like to make sure to really scrape up those browned bits—they add so much flavor to the finished stew.

Cover the Dutch oven with a lid and carefully transfer it to the preheated 350°F oven. Let the stew braise for 3–3 1/2 hours, or until the beef is very tender. Once done, remove the pot from the oven and discard the thyme sprigs and bay leaves. Stir in the frozen peas (if using) and let the stew rest, covered, for 15 minutes before serving. This rest helps the flavors come together. For a deeper flavor, I sometimes add a splash more coffee or a bit of fresh thyme just before serving.