2) Add the beef and saute, stirring occasionally, until brown on all sides, about 5 minutes. Add wine and thyme, stir well, and bring to boil.
3) Add the tomatoes, salt and pepper, then lower heat to moderately low, cover, and simmer, stirring every 15 minutes, until the beef is tender, about 2 hours.
4) When the beef is tender, use tongs to remove the tomato skins, if desired and the thyme sprigs. Turn the polenta out of the bowl, slice and serve alongside the stew.
For the polenta:
1) While the beef is simmering, make the polenta. Pour the olive oil into a large serving bowl and swirl to coat. Set aside.
2) In a heavy, large pan over a moderately-high heat, bring the stock to a boil. Lower the heat to moderate and gradually whisk in the polenta, stirring constantly. Continue cooking, stirring constantly, until polenta thickens and pulls away from sides of pan, about 5 minutes.
3) Transfer the polenta to the oil-coated serving bowl and keep warm. Let the polenta sit for 5 to 10 minutes so it can set up.