Preheat the oven to 375 degrees F. Heat the oil in a large skillet over medium-high heat. Season chicken with salt and pepper, and then coat in flour, shaking of excess. Brown the chicken on both sides and then place in a casserole dish. Drain the fat from the skillet, and then add the tomato sauce, garlic, cumin, sugar and stock or water. Bring to a boil, season with salt and pepper, and then pour over chicken. Cover and bake 25-30 minutes, or until chicken is cooked. Sprinkle with mint or parsley and serve.