Over high heat, pour sufficient oil to cover the bottom of a large Dutch oven or other large heavy pot (I use a large French enameled iron pot), generously salt and pepper both sides of the roast and sear meat until well browned on both sides. Remove meat and pour off oil.
Return pot to medium heat and add chopped carrot, celery, onion and the garlic. Cook stirring, adding a small amount of oil if necessary, until softened but not browned. Sprinkle flour over vegetables and stir for 2-3 minutes. Return meat, adding water, tomato paste