4 slices bacon, cut into small pieces
2 teaspoon salt, or more to taste
2 onions, coarsely chopped
1 can (14.9 oz) dark beer (such as Guinness®)
3 carrots, cut into 1-inch pieces
1 teaspoon white sugar
1/2 teaspoon freshly ground black pepper, or to taste
2 1/2 pounds boneless beef chuck, cut into 2-inch pieces
2 teaspoons Fat Boy Steak Rub
4 cloves garlic, minced
1/4 cup tomato paste
4 sprigs fresh thyme
2 stalks celery, cut into 1-inch pieces
2 1/2 cups chicken broth, or as needed to cover
Cook and stir bacon in a heavy skillet over medium-high heat until bacon is browned and crisp, 3 to 4 minutes. Turn off heat and transfer bacon into a large stew pot, reserving bacon fat in the skillet.
Season beef chuck cubes generously with 2 teaspoons Fat Boy Steak Rub. Turn heat to high under skillet and sear beef pieces in the hot fat on both sides until browned, about 5 minutes. Place beef in stew pot with bacon, leaving fat in skillet. Turn heat down to medium; cook and stir onions in the retained fat in the skillet until lightly browned, 5 to 8 minutes; season with a large pinch of salt.
Cook garlic with onions until soft, about 1 minute; pour beer into skillet and stir with a wooden spoon, scraping up and dissolving any browned bits of food into the liquid. Pour cooking liquid from skillet into the stew pot. Stir in tomato paste, thyme sprigs, carrots, celery, sugar, salt, 1/2 teaspoon black pepper, and enough chicken broth to cover.
Bring stew to a gentle simmer, stirring to combine; reduce heat to low and cover pot. Simmer stew until beef is fork-tender, about 2 hours. Stir stew occasionally and skim fat or foam if desired.
Remove cover and raise heat to medium-high. Bring stew to a low boil and cook until stew has slightly thickened, 15 to 20 minutes. Remove and discard thyme sprigs and adjust salt and pepper to taste.