Heat oil in a heavy, cast iron pot over medium heat. Dredge roast in flour, shake off excess, and brown in hot oil on all sides.

Stir in onions, carrots, celery, garlic, and allspice; cook until lightly browned. Pour in red wine and bring to a simmer before pouring in beef broth. Reduce heat to low, cover, and cook until beef is tender, 2 to 3 hours.

Remove meat to a cutting board; allow to rest for 10 minutes.

While beef is resting, thicken cooking liquid with cornstarch. Slice beef and serve with gravy.