Dallas Hinton:

DH> When we say "tea and apple pie", we actually mean "a cup
DH> of tea and a piece of apple pie"

Again, it is not "a piece of *an* apple pie", because  `pie'
(as   well   as   `pizza')  is  here  more  natural  in  its
uncountable, substantive form.  A piece of apple pie is like
a  glass  of  water,  whereas  I  had eggs for my dinner and
bisquits and nuts with my after-dinner tea.

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