For haricot beans with celery & harissa,
follow the recipe as for Haricot beans with harissa, adding 2 chopped celery sticks to the tagine with the haricot beans, omitting the tomatoes and sugar. Stir in the harissa with half the herbs and pour in enough water to just cover the beans. Bring to the boil, then reduce the heat, cover and cook gently for 25–30 minutes. Season well and garnish with the remaining herbs.