Do you think I need to add say cornflour to my cake flour (10% protein) for Rose’s pastry recipes to have a tender crust or can I use it as is. Will 1% make a difference?

Cake flour is the lowest protein content available here - Pastry flour I think is around 9% in the USA.

Paul, flour wiith 10% protein should be fine.  Most of her American-style crusts use bleached AP or pastry flour.  As with any pie crust, be careful not to overwork it. 

Have you seen the update to her cream cheese crust on the blog?  Use heavy cream in place of the water/vinegar. 

Hope we get to see what you make!

Thanks Julie. I am using the food processor for the first time so want to give this my best effort. I have the update. Sounds divine.

Pastry dough made with heavy cream is amazing.  There is a note about it in the Pie and Pastry bible in the variations on the regular pie crust,  and once I found it…I use only heavy cream.

Thanks Bill - I will be using cream. I always follow Rose!