Wash beef, pat dry, cut into very small cubes. Place in a bowl with the onion, garlic, pepper sauce, seasoning, celery, herbs, and beef stock cube. Mix well and leave to marinate.
Heat the oil and saute the beef. Add water and gravy browning, bring to the boil. Reduce heat and simmer until tender (40+ minutes).
Mix butter and flour into a paste, add to the stew, stirring until blended. Add salt, pepper, bay leaf etc and simmer until the vegetables are tender, about 15 minutes