Vegetable tagine with lemon couscous

8 cups soaked chickpeas (start with 3cups dry chickpeas)
1 tub tomato paste
3 litres water
4 x 425g cans diced tomatoes
3.6kg pumpkin, cut into medium sized chunks
2.7kg zucchini or yellow patty-pan squash in chunks
400g green beans, trimmed, halved
2 tablespoon vegetable oil
18 cloves garlic, crushed
4 onions chopped finely
Spices:
4 tablespoon coriander seeds
4 tablespoon cumin seeds
4 tablespoon caraway seeds
4 tablespoons sweet paprika
4 tablespoons ground ginger
Using mortar and pestle, crush seeds to a fine powder. Sift into small bowl; discard husks.
In a large pot bring the water to the boil with the chickpeas, tomato paste and undrained tomatoes.
Heat oil in a frypan; cook garlic and onion, stirring, until onion softens. Add crushed spices and powdered spices; cook, stirring, until fragrant. Add this to the water chickpeas and tomatoes. Add the pumpkin when the water is boiling; return to the boil . Reduce heat; simmer, uncovered, 20 minutes. Stir in squash and beans; simmer, covered for about 10 minutes or until squash is tender.
Serve with Lemon Couscous.