Season the chuck roast generously with salt and pepper. Preheat the oven to 275°F. Heat a large Dutch oven over medium-high heat and add the olive oil. Cut the onions in half and slice the carrots into large chunks. When the oil is very hot, brown the onions on both sides, then remove them to a plate. Add the carrots to the pot and cook briefly until they get a little color, then set them aside as well. Add more oil if needed, then place the roast in the hot pot and sear it on all sides until deeply browned. Transfer the roast to a plate and pour the wine or broth into the pot to deglaze, scraping up all the browned bits from the bottom. Return the roast to the pot and pour in enough beef stock so the liquid comes about halfway up the meat. Add the browned onions, carrots, thyme, and rosemary. Cover the pot with a lid and cook in the oven for about 3 hours for a smaller roast or around 4 hours for a 4–5 lb roast, until the meat is tender and falling apart.