Maftool, Mughrabieh and Couscous are more or less the same thing. Technically they are all the same too. All made from repeated and extended wetting and rolling of Semolina flour. The more you wet and roll the bigger the size of the grain becomes. And maftool is often referred to as giant couscous or pearl couscous.
It is eventually like a pasta, cooked the same way by rehydration, usually in chicken or meat broth to make the traditional Maftool or Moghrabiyeh, or can be cooked in tomato sauce to make the traditional Csoucsoun. Otherwise it can also be used in salads, stuffings, soups...etc.
Available in 400g packs