i am with you on that about the root ginger, watch his video and you will see it should be 4 to 5 1/4 inch thick slices.
the bit i had a problem with was the garlic & ginger paste in the book 50/50 G&G 1/4 cup oil 1/4 cup water.
now is that 1 head of garlic or 10  i too have asked and no reply!
.
i have worked this out myself