1. Place beef in a large bowl. In a small bowl, whisk together flour, 2 teaspoons salt, and 1 teaspoon pepper. Sprinkle flour mixture over beef; toss to coat beef evenly.

2. Heat a 12-inch heavy-bottom skillet over medium heat. Add about 1 tablespoon canola oil; swirl to coat bottom of skillet. Heat oil to just below smoking point. Test by placing one piece of beef in pan; it should sizzle the moment it touches the pan. If beef spits, sputters, and smokes, pan is too hot; remove it from the heat to cool. If beef does not sizzle, pan is not hot enough; wait a minute or two more. Brown beef in about 8 manageable batches: Arrange 1/8 of the meat in skillet so cubes do not touch. Cook until dark crust has formed and beef easily releases from pan when lifted with tongs, about 3 minutes. Brown all sides of each piece in this manner. Transfer first batch of browned beef to large Dutch oven. Return skillet to heat. Deglaze skillet: Pour in 1/8 of the wine (about 3 ounces); use a wooden spoon to loosen bits that have cooked onto skillet. Pour wine and deglazed juices into Dutch oven. Return skillet to heat. Quickly wipe out with paper towel. Add another tablepoon canola oil; repeat process of browning beef cubes and deglazing skillet.

3. When last batch of beef is browned and skillet is deglazed, return skillet to medium-low heat. Add pancetta; cook, stirring occasionally, until golden brown, about 10 minutes. With slotted spoon, transfer pancetta to Dutch oven. Pour half the oil from skillet into a small bowl; set aside. In oil that remains in skillet, cook half the sliced onions, carrots, and parsnips, stirring often, until onions are transparent, and carrots and parsnips have softened, about 10 minutes. With slotted spoon, transfer to Dutch oven. Cook remaining half of vegetables in reserved oil from skillet; transfer to Dutch oven.

4. Prepare bouquet garnish: Place bay leaf, thyme, parsley, and peppercorns on square of cheesecloth; tie with kitchen twine; add to Dutch oven. Pour enough water into Dutch oven to barely cover meat, about 2 quarts. Bring to a boil; reduce heat, and gently simmer, partly covered, until beef is tender, about 2 1/2 hours.

5. Meanwhile, place potatoes in a medium saucepan; cover with salted water, and bring to a boil over high heat. Reduce heat; simmer, uncovered, until tender. Warm cream in a small pan over medium heat. Drain potatoes; when cool enough to handle, press through ricer into medium bowl. Stir with a wooden spoon until smooth, 1 to 2 minutes. Cut 1 stick butter into chunks; add to potatoes, and whisk to incorporate. Drizzle in hot cream, whisking constantly. Whisk in 2 teaspoons salt, 1/2 teaspoon pepper, and the nutmeg. Set aside.

6. In a large skillet over medium-high heat, melt 2 tablespoons butter; add pearl onions, and saute until golden, about 10 minutes. Remove from heat; add to Dutch oven. Return skillet to heat; add remaining 2 tablespoons butter, and melt. Add mushrooms; cook just until mushrooms release liquid, 3 to 4 minutes. Transfer to Dutch oven. Continue to simmer stew until beef is very tender and pearl onions are very soft, about 30 minutes more. Remove bouquet garni; discard.

7. Heat oven to 475 degrees. Spoon stew into individual ovenproof ramekins about 5 inches wide and 3 inches tall. Top each with large spoonful (about 1 cup) reserved mashed potatoes. Garnish each with oregano sprig. Place ramekins on baking sheet; bake until crust is golden, about 15 minutes. Serve hot.