Blend Powdered sugar, egg whites, salt and Flour in food processor.
Add boiling water.
Add melted butter.
Spread really thin batter on Teflon sheet pan.
Bake in convection oven at 130C/266F for about 12 mn.
Cut disc of 10 cm diameter and shape. 
Reserve in dry box.

Simmer Whole milk and infuse celery.
Strain add cream and poor over egg yolks and Sosa Gelcrem.
Cook at 85 C and poor over Zephyr white chocolate.
Burr mix. 
Chill.

Soften butter.
With paddle attachment, add butter to dry ingredients.
Chill on sheet pan.
Bake at 170°C/338°F for about 15 mns.
Keep aside.

Combine dry solids.
Add water.
Head up to 85°C/185°F.
Add Puree and juice.
Blend.
Mature for 4 hours minimum.
Freeze in Pacojet bowl.
Spin when needed.

Infuse vanilla with milk.
Strain and combine with remaining ingredients.
Blend.
Chill in Siphon.

Simmer sugar and water and chill.
Combine with apples cubes in vacuum bag.
Vacuum at 100%.

Mix all ingredients together.
Let rest in cooler for at least an hour.
Burr mix to make a foam.