Let the roast come to room temp before you start cooking.
Preheat the oven to 350 degrees then pat the roast dry with paper towels. Season GENEROUSLY with salt and pepper on all sides and press the salt and pepper into the meat with your fingers.
In a Dutch oven or large oven safe pot, melt the butter then add the olive oil. Sear the meat over medium to medium-high heat on all sides then remove it from the pot.
Add the onions to the pot, grate in the garlic, season with salt and pepper and cook 3-4 minutes until the onions begin to soften. Add the tomato paste and Worcestershire sauce and cook 2 minutes.
Pour in the wine scraping the brown bits from the bottom of the pot and cook for 2-3 minutes letting the wine reduce. Stir in the stock, add the fresh thyme and rosemary sprigs then return the roast to the pot. Cover and bake 2 hours, turning the roast over about halfway through.
Peel the potatoes and carrots, season them with salt and pepper and after the roast has cooked 2 hours, add the carrots and potatoes to the pot. Cover and return the roast to the oven for about another hour or until the meat and vegetables are tender.
TIP: Roasting time will vary depending upon the size of the roast. If your roast isn’t fork tender at 3 hours continue cooking, checking every 15 minutes. If the potatoes and carrots are done before the roast, remove them from the pot and let the roast finish cooking.
Carefully transfer the roast, potatoes and carrots from the pot to a serving platter, cover it with foil then strain the herbs out of the pot.
Gravy: In a small mixing bowl combine the cornstarch and water. Bring the braised liquid to a slow boil then add to the pot, whisking constantly cooking 2-3 inutes until the gravy thickens. Taste and adjust salt and pepper as necessary.