Cook the onions till soft; fry off the spices, garlic and tomato paste.
Add the vegetables, lemon juice and enough stock to barely cover the vegetables.
Simmer 30 minutes until tender.
Add the chickpeas, parsley and coriander stalks and heat through for 5-10 minutes.
Serve with chopped coriander leaves.
Couscous is a good accompaniment: you could use the herbs to garnish the couscous rather than the tagine. Pomegranate seeds and/or toasted cashew nuts are excellent additions.