Like French toast for one chap on vacation (4)
I believe the answer is:
eggy
'like french toast' is the definition.
(I've seen this in another clue)
'for one chap on vacation' is the wordplay.
'for one' becomes 'eg' (both can mean 'for example').
'chap' becomes 'Guy'.
'on vacation' means to remove the middle letters (after the inside letters have vacated the word).
'guy' with its middle taken out is 'gy'.
'eg'+'gy'='EGGY'
(Other definitions for eggy that I've seen before include "Yolky?" , "with a sulphurous niff?" , "Like part of breakfast" , "Like things hens lay" , "Like an omelette" .)