Football supporter possibly consuming large tart (4)
I believe the answer is:
flan
'tart' is the definition.
(type of tart)
'football supporter possibly consuming large' is the wordplay.
I cannot quite understand how this works, but
'large' could be 'l' (eg in clothes sizes) and 'l' is found within the answer.
'supporter' could be 'fan' (fan is a kind of supporter) and 'fan' is found in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for flan that I've seen before include "Flat open tart" , "Open-topped pastry dish" , "dish, sweet or savoury" , "Open pastry case with savoury filling" , "Quiche-like dish" .)