To finish with I have salad food (6)
I believe the answer is:
endive
'salad food' is the definition.
'endive' can be an answer for 'food' (endive is a kind of food). I'm not sure about the 'salad' bit.
'to finish with i have' is the wordplay.
'to finish' becomes 'end' ('end' can be a synonym of 'finish').
'with' means one lot of letters go next to another.
'i have' becomes 'I've' (contraction of 'I have').
'end'+'ive'='ENDIVE'
Can you help me to learn more?
(Other definitions for endive that I've seen before include "Salad plant related to chicory" , "Envied (anag.)" , "Portion of salad" , "Plant used in salads" , "Edible plant" .)