London Eye? That's Xmas treat! (5,3)
I believe the answer is:
mince pie
This clue could be a double definition.
'london eye?' is the first definition.
'mince pie' can be an answer for 'eye?' (I've seen this before). I am not certain of the 'london' bit.
'xmas treat' is the second definition.
(I've seen this before)
'that's' is the link.
Can you help me to learn more?
(Other definitions for mince pie that I've seen before include "Xmas treat" , "Christmas treat" , "Christmas food item" , "Fruit-filled tart" , "festive treats" .)