They are not interchangeable.

Dans la cuisine is far more frequent and just states "located in the kitchen" (physical location).

En cuisine means in (a/the/some) kitchen, usually a professional one like in a restaurant, but for a reason related to the purpose of the place (functional location).

You’ll find similar nuances with:

Le train entre en gare / le train entre dans la gare.

Je suis arrivé en prison / je suis arrivé à la prison.