Hot food is not healthy, covered in sliced potato mostly (6)
I believe the answer is:
chilli
'hot food' is the definition.
'chilli' can be an answer for 'food' (chilli is a kind of food). I'm unsure of the 'hot' bit.
'not healthy covered in sliced potato mostly' is the wordplay.
'not healthy' becomes 'i'll' (I've seen this in another clue).
'covered in' indicates putting letters inside.
'sliced potato mostly' becomes 'chi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ill' put inside 'chi' is 'CHILLI'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for chilli that I've seen before include "Hot one in dish maybe" , "Burner" , "Type of capsicum" , "Small hot pod" , "Hot food (that sounds cold!)" .)