Ingredients for a 1 US Pint Whipper:
Peel the potatoes and boil them with the celery in salt water until done and pass through a sieve (do not puree with a mixer!). Mix with vegetable stock and season to taste. Pass through the iSi Funnel + Sieve directly into the 1 US Pint Whipper.
Screw on one N20 Cream Charger and shake vigorously. Keep hot in the Whipper, in a bain-marie or in a water bath.
Serve as a starter with fresh herbs.