Hey, thanks for the feedback.
In the main menu (before you select a kitchen and recipee) if you go to the options, then to the gameplay options, you can enable/disable the tutorial.
In the same gameplay options menu, you can also set a time scale, which allows you to change the timer by a factor (e.g. 4x will mean a 20 minute timer will be 5 minutes).
Currently, the instructions on the whiteboard will still say 20 minutes and not the scaled time, this will be fixed in a future release. I'm also going to be adding a 'progress time' mechnic which allows you to speed up time whilst waiting.
Hope that helps,