Remove the core of the apples and chop roughly. Finely chop one celery stick and keep aside.
Warm a pan over low heat. Heat a spoon of oil, add chopped onion and bay leaf and sauté till translucent.
Add apples and chopped celery to the pan and sauté for another 5 minutes on medium heat
Add the vegetable stock and seasoning. Mix well. Cover and bring to a boil. Simmer for 15 mins till the ingredients soften.
Once the soup is well cooked, remove the bay leaf and puree until smooth.
Strain the soup through fine sieve and mix in a spoon of cream. Adjust seasoning.
In another pan, toast walnuts over medium heat. Ensure that pan is shaken well during the process to prevent burning. Allow the nuts to cool.
Once cooled down, grind the walnuts to a fine powder and strain to prepare walnut dust.
Celery cream caviar
Mince the second celery stick and pass it through a sieve. In pan, add this minced celery, the remaining cream, salt, agar agar powder and bring to a boil. Once done, pour the mixture through a dropper into chilled oil.
Using a spoon, gently remove the freshly made celery cream caviar and wash the pearls under running water.
In a soup bowl, pipe droplets of the churned cream. Intersperse the droplets with the apple slices.
Arrange the caviar in the rest of the bowl and sprinkle the walnut dust.