Dislike eating meat I cooked? It's a source of iron (9)
I believe the answer is:
haematite
'a source of iron' is the definition.
(I've seen this before)
'dislike eating meat i cooked?' is the wordplay.
'dislike' becomes 'hate' (to hate is to dislike strongly).
'eating' means one lot of letters goes inside another.
'cooked?' indicates anagramming the letters (letters cooked into a new form).
'meat'+'i'='meati'
'meati' anagrammed gives 'emati'.
'hate' enclosing 'emati' is 'HAEMATITE'.
'it's' acts as a link.
(Other definitions for haematite that I've seen before include "Iron ore" , "source of iron" .)