Let's say the cooking time for a dish is 50 minutes. I want to ask how much time remains between now and when the dish will be done.
What is the right way to ask that?
You could go about it a couple of ways. One would be to straight up ask what you basically already said:
How much time remains for [insert action/activity/etc. here]?
Or you could say something along these lines:
How much longer will this take?
You could (if you wanted) replace "this" with whatever thing you're asking about.
How much longer will the dish be cooking?