My mom gave her approval to my fancy-pants additions of brûleéd (blackened) onions and tomatoes, but I dare not mess with the Lipton Onion Soup Mix, because it works some sort of mysterious processed magic here; I am a believer. Historically, this beef stews slowly overnight in a crockpot, but I like to bake it in the oven for five hours at a slowly decreasing temperature, maintaining a gentle burble in the braising liquid, until the meat fibers become soft enough to be pulled like taffy. —Amy Thielen
Heat a 12-inch cast-iron skillet over medium-high heat and brûleé the onions and tomatoes—onions first. Lop the tops off the onions and just shave the root ends to leave them intact, peel off the papery skin, and halve them crosswise, along their equators. (To facilitate clean-up, you may line the pan with a single layer of foil.) Lay the onions face-down in the hot, dry pan and cook, over a controlled high heat, until their rings turn frankly black and the tops remain uncooked, about 15 minutes. Remove and reserve. Halve the roma tomatoes and roast them in the same face-down fashion in the pan, until blackened on the edges. Reserve.
Slice the chuck roast into 3-inch-thick slabs, and layer in a heavy braising covered braising pot, such as a Le Creuset braiser. Mix together the onion soup mix, thyme, salt, and pepper, and sprinkle evenly over the meat. Add the soy sauce and Worcestershire, and mix with your hands to coat. Tuck in the brûleéd onions and tomatoes, garlic, and bay leaves, add the beef stock and then enough water to reach 1/2 inch below the surface of the meat. (You want the beef to iceberg above the braising liquid.)
Cover the pot with a heavy lid, and bake at 325° F. for one hour, then turn the oven down to 300° F. and cook another two hours, until the meat is tender-ish. The liquid should be bubbling gently. Set the lid offset, turn the oven down to 250° F. and bake for another two hours, or until the meat is fully tender but still moist. (At this point you may cool the braised beef to room temperature, cover, and refrigerate for serving the following day.)
Pull out the onions, tomatoes and bay leaves, and then using a small ladle, skim off the excess fat pooling on the surface. (Discard, or save the vegetables and excess fat to enrich a pan of cooked beans.) With tongs, pull and twist the meat until gently shredded. Serve the warm meat on sliced crusty buns, with plenty of juice, topped with an optional bread-and-butter or pepperoncini.