Heat the oil in the bottom of a tagine or a large Dutch oven. Saute the onion and garlic over moderate heat until onion is translucent and soft, about 5 minutes. Either move to side of pan or set aside while browning chicken pieces.

Raise the heat, add the chicken pieces, and brown evenly turning often. Add the turmeric, cilantro, chicken stock, salt, pepper and bring to a simmer.

Meanwhile rinse the pieces of lemon in cold running water and with a sharp chef knife trim the flesh and white pith of the lemon and discard. Cut the softened rind into thin strips and stir into the chicken. Return the onion and garlic to the chicken if previously set aside.

Cover and cook very slowly for about 90 minutes. Remove lid and if necessary, boil rapidly to reduce and thicken.

Garnish with fresh cilantro before serving with couscous.