Finding many actors, but just choosing one! (7,4)

I believe the answer is:

casting lots

I'm a little stuck... Click here to teach me more about this clue!

'actors but just choosing one' is the definition.
I can't judge whether this defines the answer.

'finding many' is the wordplay.
'finding' becomes 'casting' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'many' becomes 'lots' (lots of something).
'casting'+'lots'='CASTING LOTS'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.