The traditional way to prepare this chicken dish from Michoacan, is in a clay casserole dish covered with a sealing layer of ground corn or masa. Small bits of the corn mixture break off and add a thickening texture to the sauce. This modern version is much simpler to prepare. Rub the chicken with the garlic, salt, and pepper and refrigerate for 2 to 4 hours. In a large skillet, heat the corn oil, saute the chicken briefly and transfer to a cazuela or large pot. In the same oil, lightly brown the potatoes, remove, and set aside. Add the vinegar to the skillet and bring to a boil, scraping up browned bits from the bottom of the skillet. Pour the vinegar through a strainer over the chicken. Add the olive oil, salt, bay leaves, thyme, and marjoram to the chicken cazuela. Bring to a boil over high heat, cover, and lower the heat. Every 10 minutes, uncover and stir. After 35 minutes, uncover, correct the seasonings, and add the chilies and potatoes. Cover and cook over low heat until the potatoes are tender, about 15 minutes.