Amos is confusing his apples and potatoes. Pommes de terre (apples of the earth) or Pommes Frit (fried potatoes, which works out fried apples of the earth) are not the same as the pome, not to be confused with a drupe or a berry or a nut. . .

An exerpt from the Robert Service poem, Babette (so I can include poetry and BS at the same time):

The poor little supper she offers
Is more than a banquet to me;
A different bif-tik she proffers,
Pommes frit and a morsel of Brie;
We finish with coffee and kisses,
Then sit on the sofa and pet . . .
At the Embassy Mumm never misses,
But pinard's my drink with Babette.