North african pumpkin & chickpea stew

2 large onions, diced

2 cloves garlic, chopped
1 stick celery, diced
1 tsp turmeric
1/2 tsp cinnamon
1/2 tsp ground ginger
8 saffron threads, toasted
1/2 cup red lentils, rinsed
400g tin chickpeas, rinsed
500ml passata
bunch coriander
300g butternut pumpkin
1L veg stock
1/4 cup risoni

From HFW's "River Cottage, Veg everyday"