Step 1Remove the rind, cut the bacon into lardons (sticks, 1/4 inch thick and 1 1/2 inches long). Simmer the rind and bacon in 1 1/2 quarts of water 10 minutes. Drain and dry.
Step 2Heat the oven to 450 degrees.
Step 3Cook the bacon in 1 tablespoon of the oil over moderate heat in a 5- to 6-quart heavy, flameproof casserole until lightly browned, 2 to 3 minutes. Remove to a large bowl with a slotted spoon. Reheat the casserole until the fat is almost smoking before you cook the beef.
Step 4Dry the beef with paper towels; it will not brown if it is damp. Cook it, a few pieces at a time, in the hot oil and bacon fat until nicely browned on all sides. Add it to the bacon in the bowl.
Step 5In the same fat, brown the mushrooms over medium heat and set aside (if there is no fat left in the pan, add 1 tablespoon of olive oil to brown the mushrooms). Add the carrot and brown onion and cook until browned, 4 to 5 minutes. Pour out any fat.
Step 6Return the beef to the casserole with the vegetables and toss with the salt and pepper. Sprinkle on the flour and toss again to coat the beef lightly. Set the casserole uncovered in the oven for 4 minutes. Toss the meat and return to the oven 4 minutes more. (This browns the flour and covers the meat with a light crust.) Remove the casserole and turn the oven down to 325 degrees.
Step 7Stir in the wine and enough stock so that the meat is barely covered. Add the tomato paste, garlic, thyme, bay leaf and the bacon rind. Bring to a simmer on top of the stove. Cover the casserole and set in the lower third of the oven. Regulate the heat so the liquid simmers very slowly for 2 to 2 1/2 hours. The meat is done when a fork pierces it easily.
Step 8Meanwhile, heat the butter and the remaining 1 tablespoon of olive oil in a skillet over medium heat. When the butter foams, add the boiling onions. Cook, stirring the onions, so they brown evenly, about 5 minutes. When the beef is halfway done, add the onions to the casserole to finish cooking.
Step 9When the meat is tender, pour the contents of the casserole into a sieve set over a saucepan. Wash out the casserole (if you're serving the stew from it at the table) and return the beef, vegetables and bacon to it.
Step 10Skim the fat from the sauce, if necessary, and simmer the sauce a minute or two, skimming off additional fat as it rises. You should have about 2 1/2 cups of sauce thick enough to coat a spoon lightly. If too thin, boil it down rapidly. If too thick, mix in a few tablespoons of stock. Taste carefully for seasoning. Pour the sauce over the meat, vegetables and mushrooms. Simmer 2 to 3 minutes, basting the meat and vegetables with the sauce several times. Serve from the casserole, or arrange on a large deep platter and serve, decorated with the parsley.