Remove the skin from the chicken. Cut off all excess fat and then chop the thighs into two pieces, at the level of the joint. Put aside.

Next, prepare the marinade. In a large bowl, add the soy sauce, dried parsley, ground cumin, ají amarillo chili paste, muscovado sugar, salt, and pepper to taste. Stir.

Peel and mash the garlic. Add them to the marinade. Stir well until you get a smooth paste.

Place the chicken pieces in the bowl, and rub the chicken pieces with the seasoned sauce. Make sure all chicken pieces are well covered. Let the chicken rest for at least an hour.

Peel the onion, and cut it into large pieces. Coarsely chop the parsley and cilantro as well. Remove the stem from the rocoto peppers. You can remove the veins and seeds if you do not want the sauce to be spicy. However, if you want hot sauce, add the whole peppers to the blender glass.

Immediately place the coriander, parsley, onion, sour cream, vinegar, hot peppers, lime juice, salt and pepper in the blender and process for about three minutes until the sauce is the desired consistency. Some people like the sauce to be smooth, while others like to feel pieces of parsley or coriander in it. It is a matter of taste. Taste and adjust the salt. Pour the sauce into a serving bowl.

Lastly, turn the stove to high heat. Put a grill pan on top of the stove and wait at least three minutes until it has heated up very well. Then place the chicken pieces with the meatiest side down. Cook them for about five minutes, and immediately turn them over, lower the heat (to the 'low' setting) and cook covered for another fifteen minutes so that the chicken cooks well through. If your chicken pieces are very large, add a half cup of water to the skillet after flipping the meat to ensure optimal doneness. Serve with plenty of green sauce and fried yuquitas.