1. Mix together the garlic, oregano, salt, pepper and vinegar and rub into the chicken pieces. Let stand for 1 hour.Heat the oil in a frying pan and sauté the drained chicken pieces until golden. Transfer to an earthenware casserole. Add any remaining marinade. In the remaining oil saute the onion and bell pepper until the onion is lightly browned. Add the contents of the pan to the casserole with the tomatoes, bay leaf, ham, coriander, and 1 cup of chicken stock. Cover and simmer for 50 minutes. Lift out the chicken pieces and other solids and set aside. Measure the liquid and add enough chicken stock to make up to 3 cups. Pour into a saucepan and bring to a boil.
2. Wash the rice, drain and pour into the casserole. Add the boiling stock and stir. Add the capers, olives, chicken pieces, and other solids. Cover and cook over low hear until the liquid has absorbed and the rice is tender. Discard the bay leaf. Sprinkle the rice with the sherry and garnish with peas and pepper; heat through. Serve directly from the casserole.