In a Dutch oven, heat oil over medium heat. Brown meat on all sides. Remove from pan. Add onions to the same pan; cook and stir until crisp-tender, 5-7 minutes. Add garlic; cook and stir 1 minute longer. Add water, stirring to loosen browned bits from pan. Stir in Worcestershire sauce, bay leaf, oregano, salt, pepper. Return meat to pan; bring to a boil. Reduce heat; cover and simmer until meat is tender, 1-1/2 to 2 hours., Add potatoes and carrots. Continue to cook until vegetables are tender, 30-45 minutes. Remove and discard bay leaf. In a small bowl, mix flour and cold water until smooth; stir into Dutch oven. Bring to a boil; cook and stir until thickened, 1-2 minutes. If desired, stir in browning sauce.