This is a great one-pot meal - but you can also serve with rice (try "hapa" rice, which is a mix of ½ brown and ½ white - or go 100% brown rice).
Season the roast with garlic salt and pepper, then heat a large dutch oven (or any large pot with a cover) over medium high head and add the oil. Brown all sides of the roast. Whisk the tomato paste into the beef stock and pour the resulting mixture into the pot. Add the onion, garlic, bay leaves, rosemary, and salt and pepper and bring to a brisk boil, then reduce the heat to low and gently simmer with a covered lid for about 45 minutes. Turn the roast over and simmer for an additional 45 minutes, then add in the carrots and bring the liquid back to a gentle simmer. Cover and cook for 45 more minutes then add in the potatoes, bringing the liquid back to a simmer. Cook for an additional ½ hour or until the potatoes are cooked but still firm (adding the potatoes last ensures that they don't fall apart).
If the liquid in the pot evaporates too much during the cooking process, just add in water, about a cup at a time. Toward the end of the cooking process, let the liquid thicken (you can even uncover the pot after adding the potatoes to encourage thickening). To serve, slice the roast into thick pieces and plate each serving with some carrots and potatoes, ladling over some of the sauce.