Cook bacon in a heavy skillet over medium-high heat until it's browned and crisp, which should take about 3 to 4 minutes.
Turn off the heat and place the cooked bacon into a large stew pot. Keep the bacon fat in the skillet for later use.
Season the beef chuck cubes with 1 teaspoon of salt and some black pepper according to your taste.
Heat the skillet again, this time on high, and cook the beef in the bacon fat. Make sure to brown the beef on both sides, which will take about 5 minutes.
After browning, transfer the beef to the stew pot with the bacon. Don't clean the skillet; leave the fat in there.
Reduce the skillet heat to medium and cook the onions in the fat until they are lightly browned, which should take about 5 to 8 minutes. Add a large pinch of salt to the onions.
Add garlic to the onions and cook until soft, roughly 1 minute.
Pour beer into the skillet. Use a wooden spoon to stir and scrape up any browned bits from the bottom of the skillet. This helps add flavor to the stew.
Move the cooking liquid from the skillet to the stew pot.
To the stew pot, add tomato paste, carrots, celery, thyme sprigs, sugar, ½ teaspoon black pepper, and enough chicken broth to cover everything.
Mix everything in the pot well, then bring the stew to a gentle simmer. Cover the pot, reduce heat to low, and let it simmer until the beef is very tender, about 2 hours. Stir the stew occasionally.
After 2 hours, remove the pot cover, increase the heat to medium-high, and cook until the stew thickens a bit, which should take about 15 to 20 minutes.
Take out and throw away the thyme sprigs. Taste the stew and add more salt and pepper if you think it needs it.
Serve the stew by placing mashed potatoes in a ring shape in a serving bowl and ladle the stew into the center of the mashed potatoes.