Heat the margarine on a low to medium setting in a saucepan. Add the onions and curry powder, cook for 2-3 minutes until soft.
Now add the parsnip and celery to the pan and cook for 5-6 minutes, stirring regularly. Add the pear thereafter.
Pour the vegetable stock into the pan and bring to the boil. Reduce the heat and simmer for 35-40 minutes.
Remove the pan from the hob and add the yoghurt. Put the contents into a blender and blend until the consistency is smooth. Season to taste and pass the soup through a strainer into a saucepan.
To make the onion bhajis, sprinkle salt onto the onions in a bowl. Leave for 4-5 minutes to let the onions soften and release liquid.
In with the onion bhajis, combine the turmeric, coriander, cumin and flour to make a paste – leave to stand for 5 minutes. If the paste doesn’t form, add a small splash of cold water.
Fill a small, deep saucepan with oil to halfway. Heat to 170°C/325°F. Using a serving spoon, carefully drop the battered onions into the hot oil.
Fry the bhajis for 2-3 minutes until they appear bronzed and crispy. Remove from oil and pat dry with kitchen towel to get rid of excess oil.
To make the curry oil, toast the curry powder in a dry frying pan over a low-medium heat for 1-2 minutes. This releases the flavours from the powder. Add the rapeseed oil and stir gently for 3-4 minutes.
Remove the pan from the heat and leave to cool. Pass the liquid through a strainer into a bowl.
Reheat the soup in a pan over a low heat, to serve. Put the soup into bowls and place a bhaji in the middle of each, then drizzle the curry oil on top. Serve immediately.