Prepare Bacon and Render Fat: In a large heavy skillet over medium-high heat, cook the chopped bacon until it’s crispy and browned, about 3 to 4 minutes. Remove the bacon with a slotted spoon and transfer it to a large stew pot. Leave the rendered bacon fat in the skillet for searing the beef.
Season and Sear Beef: Season the beef cubes generously with 1 teaspoon salt and freshly ground black pepper. Increase heat to high and sear the beef pieces in the hot bacon fat, browning all sides for about 5 minutes. Transfer the browned beef to the stew pot with the bacon. Keep the fat in the skillet.
Cook Aromatics: Lower the heat to medium. Add the chopped onions to the skillet and sauté in the bacon fat until they soften and turn golden, about 5 to 8 minutes. Sprinkle a pinch of salt over the onions to help draw out moisture. Add the minced garlic and cook for another minute until fragrant.
Deglaze with Beer: Pour the dark beer into the skillet with the onions and garlic, stirring well. Use a wooden spoon to scrape up all the browned bits stuck to the pan’s bottom, dissolving them into the liquid to build rich flavor.
Combine Ingredients in Pot: Pour the beer-onion mixture into the stew pot with beef and bacon. Add tomato paste, carrots, celery, thyme sprigs, sugar, ½ teaspoon black pepper, and enough chicken stock to cover the ingredients completely.
Simmer the Stew: Bring the stew to a gentle simmer over medium heat. Once simmering, reduce the heat to low and cover the pot. Let it cook slowly for about 2 hours, stirring occasionally and skimming off any fat or foam that rises to the surface.
Thicken the Stew: After 2 hours, remove the lid and increase heat to medium-high. Allow the stew to simmer uncovered for 15 to 20 minutes, stirring occasionally, until the liquid thickens slightly. Remove and discard the thyme sprigs.
Final Seasoning and Serve: Taste and adjust seasoning with additional salt and pepper if needed. For a classic presentation, arrange mashed potatoes in a ring on a serving dish and ladle the stew into the center. Serve hot and enjoy!