Cut beef into 2 by 3 inch cubes and season with salt and pepper.
In an 8 quart heavy bottomed Dutch oven, heat oil and butter over medium heat until foam subsides. Brown beef pieces 4 to 5 at a time until dark golden brown, about 12 to 20 minutes. This step cannot be shortened, it is essential! When meat is done, remove last pieces and add onions, carrots and turnips and cook until brown bits on bottom of pan have softened and loosened. Add stock, tomato sauce and wine and bring to a boil. Add beef pieces and return to boil. Lower heat to simmer, cover and cook 1 1/2 to 2 hours until meat is very tender. Remove and serve with Risotto Alla Milanese.
Saute the onion and garlic in the olive oil over medium heat until translucent, but not brown (about 10 minutes). Add the thyme and carrot and cook 5 minutes more. Add the tomatoes. Bring to a boil, lower the heat to just bubbling, stirring occasionally for 30 minutes. Season with salt to taste. Serve immediately, or set aside for further use. The sauce may be refrigerated for up to one week or frozen for up to 6 months.