Sharp comment with indication about energy in cooking device (8)
I believe the answer is:
barbecue
'cooking device' is the definition.
(a barbecue is used for cooking)
'sharp comment with indication about energy' is the wordplay.
'sharp comment' becomes 'barb' (a barb is a sharp or hurtful remark).
'with' means one lot of letters go next to another.
'indication' becomes 'cue'.
'about' says to put letters next to each other.
'energy' becomes 'e' (physics symbol as in E=mc2).
'cue' after 'e' is 'ecue'.
'barb' put next to 'ecue' is 'BARBECUE'.
'in' acts as a link.
(Other definitions for barbecue that I've seen before include "Open-air party with roast meats etc" , "cook burgers, say" , "Grill over an open fire" , "Outdoor meal - grill used to cook it" , "Grill for outdoor cooking" .)