The plane has its own chefs-kitchen. Just bring the chef with them. Btw their staff loves them and is very devoted.
https://www.youtube.com/watch?v=EgWVGNmORJs
You may find this interesting. It about Trumps Plane (T Bird).
It is more suited for finishing pre-prepared restaurant meals from his restaurants. The meals are close to being done, but not just re-heated. I don’t think quality is affected much. I watched a documentary on his plane. Was an hour long. That is what the kitchen is designed for.