How many what?
I assumed people.
Maybe that's just me.
We don't know, it's context dependent. Can be bread, steaks, cakes, anything..
The people who said that, are seeing the scene, so they know what is cooking the other person. But us, we can't see it.
Could 'sunt' be used in this sentence, or is it unnecessary because 'quot' extends to cover 'how many [are]'?