Trim any excess fat from the beef, if needed. Cut the beef into 8 slices, each about 1/2 inch (1.5 cm) thick. Place each slice between sheets of plastic wrap and pound both sides with a meat mallet. Arrange the slices on a tray and season with salt and pepper.

Dredge the beef slices in flour, shaking off any excess. Heat a large skillet with the vegetable oil, brown the beef on both sides, and transfer to a high-sided baking dish.

Using the same skillet without cleaning it, add a little more oil if needed and sauté the onion and garlic until golden.

Add the celery, carrot, and wine. Let the wine reduce by half. Add the tomato sauce, diced tomatoes, oregano, thyme, bay leaf, beef broth or water, salt, and sugar.

Mix well, bring to a boil, and pour the sauce over the beef in the baking dish. Cover the dish with aluminum foil and place in a preheated oven at 350°F (176°C). Bake the beef for about 80 minutes, until very tender.