Heat vegetable oil in a stockpot over medium heat. Cook beef until browned on all sides, 2 to 4 minutes per side. Stir in onion, carrots, and celery.
Mix water, gravy mix, and bouillon together in a small bowl; pour into stockpot. Stir in Worcestershire sauce, chili powder, and oregano.
Cover stockpot, reduce heat to low, and simmer for 1 hour. Stir in potatoes, cover, and simmer until potatoes are easily pierced with a fork, about 30 minutes more. Season with salt and pepper.