Going to put half of them in the hot oven to cook (2,3,4)

'going' is the definition.
Both the definition and answer are adjectives. Maybe there's an association between them I don't understand?

'half of them in the hot oven to cook' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is found within the answer.
'them' could be 'em' (abbreviation) and 'em' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'hot' could be 'h' (abbreviation eg on taps) and 'h' is located in the answer.
an anagram of 'oven' is 'nove' which is located in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...

'to put' acts as a link.

Can you help me to learn more?