Wash meat and pat dry with paper towels.
In a Dutch oven or heavy kettle, heat the oil, add beef chunks, onion, bell pepper, oregano, garlic, and stir-fry over moderate heat until meat is brown. Add the salt, tomato sauce, achiote, olives, capers, and bay leaf. Mix and cook for 5 minutes. Add the water, bring to a rapid boil, cover, and simmer over low heat for 30 minutes. Add the potatoes, stir to combine, and bring to a rapid boil. Cover and simmer for another 30 minutes.
Serve over steamed white or yellow rice.