Accompaniment: 2 pounds roasted fingerling potatoes
Place cut beef into a large non-reactive bowl and add wine. Wrap tightly with plastic wrap and let marinate overnight in fridge.
Drain beef in colander with a bowl underneath, reserving marinade. Place flour and coarse black pepper in a shallow plate and working in batches, toss meat in flour, shaking off any excess.
In an All-Clad Dutch Oven, over medium heat, cook bacon until fat has rendered and is slightly crispy. Using a slotted spoon remove bacon from pot, leaving fat in pan and reserving cooked bacon.
Working in batches, add coated beef to pot and brown on all sides, about 8 minutes per batch. Transfer beef from pot to bowl and repeat with remaining ingredients until all meat has been browned.
Pour off any excess fat in the pan and increase heat to high. Pour sherry into pot and using a wooden spoon scrape up the bits on the bottom of the pan. Pour liquid over beef.
Using kitchen string tie together celery, parsley stems, thyme and bay leaves, making a bouquet garni.
Melt butter over medium heat in pot and add onions, garlic, and carrots and cook until onions are slightly golden, about 4 minutes. Add tomato paste and cook, stirring constantly for 1 minute. Add reserved marinade, beef with juices, cooked bacon, and bouquet garni and bring to a simmer. Cook, partially covered, until meat is tender, about 3 1/2 to 4 hours.
In a large pot of boiling salted water blanch pearl onions for 2 minutes, drain, rinse under cold water and peel. Melt 1 tablespoon of butter in a medium saucepan over high heat until foam subsides and sauté onions until brown spots appear. Add 1 3/4 cups water, bring to a simmer and partially cover. Cook until they are tender, about 20 minutes. Uncover and cook until liquid is reduced and onions are glazed.
Over high heat melt remaining tablespoon of butter in a large non-stick skillet and sauté mushrooms until they are golden and all the liquid they have released is evaporated. Season with salt and pepper.
Stir pearl onions and mushrooms into stew and cook for 15 minutes. Remove bouquet garni and skim the fat from stew. Season with salt and pepper.
Serve stew over roasted fingerling potatoes and garnish with chopped parsley.