What I like about grating frozen butter is that it goes so quickly — it takes maybe 45 - 60
seconds to grate a stick of butter, so it's not possible for it to melt, or even feel greasy on the hands (but I start with the flour / dry ingredients already on the
bowl and before I start grating, I
dredge the stick of butter
in the flour mixture so as to create a barrier between me and the actual butter).