In a large saucepan, heat the butter and saute the celery, garlic and mint.
Add the stock liquid, bring to a boil and add the peas, cook for 7 minutes. Season. Add water if you need more liquid.
Transfer the soup to a blender, and blitz until smooth. I also used a sieve to remove pieces of fiber if you need a silky smooth soup. Refrigerate until cool.
For the tuiles, lightly whisk the egg whites.
Combine with sugar, flour and butter until you have a smooth paste. Add the nuts and herbs.
On baking paper, spread small amounts of paste into a very thin circle. Bake for 4 minutes at 200 degrees Celsius, until golden brown.
Remove from oven and carefully transfer the hot disks onto a rolling pin to take shape. It cools quite quickly and can be very brittle.