Chop the onion and fry in the oil until transparent.Finely peel and chop the garlic and ginger and add to the onion with the spices and stock. Cook for 5 minutes. Peel and remove the seeds from the squash. Dice and then add to the onion mixture. Fry until it starts to brown. Then cover with water and simmer for 10 minutes or until soft. Blend until creamy and then season to taste.