Thanks, Migoya. Instant magic pastry method worked!
There is a vague eggy taste, may be due to the stray egg whites.
Compared to the PC at Glacé, this is a lot looser. Anyway, I made a mistake. I forgot to add the sugar to the milk, added after the hot milk had been whisked in and mixture coagulated. The mixture became more liquid after the sugar was added. I wonder if it would have made much more difference.
Combine B and sieve to remove lumps. Heat A to rolling boil. Dump into B all at once, whisking constantly. Add C when cool.
Note: Found updated recipe.
Made 30x40cm sheet genoise with following:
HK flour 190/156
Heated egg and sugar to about 60C. Beat at high speed until volume almost there, then switched to medium/low speed for smaller air bubbles and finer texture. Added milk, beat til desired volume. Folded in flour in 3 additions. Folded in butter. Transferred to sheet pan and evened top. Baked for 23 mins at 170C, rotated halfway.
As you can see the cake is rather high. Was using first set of weights, batter filled pan to the brim.
New frosting yay! It is quite temperature stable. Great for rustic home made looking cakes. Will consider reducing sugar next time and adding a little salt.
Photos taken every 10 mins apart. It is holding its shape. I am happy.
Cooked Flour Frosting
Bread flour 17
Softened butter 113
Bring milk, flour and sugar to boil. Boil for one minute. Don’t stop stirring. Allow to cool completely.
Beat butter until fluffy. Add cooled milk mixture and beat until fluffy.