Turn up the gas ring to cook it (4)
I believe the answer is:
sago
'cook it' is the definition.
I can't tell whether this definition defines the answer.
'turn up the gas ring' is the wordplay.
'turn up' shows that the letters should be reversed in order.
'ring' becomes 'O' (letter resembling a ring).
'gas' written backwards gives 'sag'.
'sag'+'o'='SAGO'
'to' is the link.
Can you help me to learn more?
(Other definitions for sago that I've seen before include "Starchy cereal used in puddings" , "Type of milk pudding" , "Edible powdery starch" , "Starchy pudding cereal" , "Starchy food as white pudding" .)