Which fireworks give the heavens some lettuces? (10)

'some lettuces?' is the definition.
Although both the answer and definition are plural nouns, I cannot see how one could define the other.

'which fireworks give the heavens' is the wordplay.
I cannot really see how this works, but
'fireworks' could be 'rockets' (rocket is a kind of firework) and 'rockets' is present in the answer.
'heavens' could be 'sky' (sky is a kind of heavens) and 'sky' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?