If sly as can be, you can eat it (7)
I believe the answer is:
salsify
'can eat it' is the definition.
I can't tell whether this definition defines the answer.
'if sly as can be' is the wordplay.
'can be' is an anagram indicator.
'if'+'sly'+'as'='ifslyas'
'ifslyas' is an anagram of 'SALSIFY'.
'you' is the link.
Can you help me to learn more?
(Other definitions for salsify that I've seen before include "Existence" , "Oyster plant" , "edible plant" , "Edible root, eaten cooked -- fils, say (anag)" .)