PREPARATION:

1. Peel the onion and chop it roughly. Peel and crush the garlic and put it with the onion into a medium-sized, heavy saucepan. Peel the ginger, cut it into thin shreds and stir that in too. Add the lentils and pour in 1 1/2 litres (6 cups) of water. Bring to the boil, then turn the heat down to an enthusiastic simmer. Stir in the ground turmeric and chili, season and leave to simmer, covered, for twenty minutes.
2. While the soup is cooking, bring a medium-size pan of water to the boil. Peel the pumpkin and scoop out the seeds and fibre, then cut the flesh into fat chunks. Boil the pumpkin pieces for ten minutes, until they are tender enough to take a skewer without much pressure. Drain them and set aside.
3. To make the onion topping, peel the onions and cut them into thin rings. Cook them in the oil in a shallow pan until they start to colour. Cut the chilies in half, scrape out the seeds and slice the flesh finely. Peel and finely slice the garlic and add it with the chilies to the onions. Continue cooking until the onions are a deep golden brown. Set aside.
4. Remove the lid from the lentils and turn up the heat, boiling hard for 5 minutes. Remove the pan from the heat, then add the drained pumpkin. Put the soup through the blender until smooth, then pour it into a bowl. Stir in the roughly chopped coriander and check the seasoning. I find this soup likes a more generous than usual amount of salt.
5. Serve in deep bowls with a spoonful of the spiced onions on top.