If you carry a tiny camping pot (~ I use a 1/2l one which is enough for me), a plastic container that can be used in the microwave (+lid), a spork and an opinel, that's enough to prepare a meal and you can take the leftovers with you in the container. For kitchens like that it is also good to carry a tiny amount of salt and cooking oil, and some instant coffee/tea bags, because there usually won't be any in the kitchen.
The small pot doubles as a cup for coffee/tea/wine. The microwaveable container can be used in case of no oven but at least microwave, and also to prepare cold food (salad). The lid works as a plate for cutting bread or fruits ect.
I've used that setup for a while now and am very happy with it. When there's not even a microwave, you can always prepare a salad and bread, cheese, olives, fruit, ect.ect.
A tiny, lightweight cooking pot can be bought at Decathlon, for example. Some models of camping pots have lids that also work as a frying pan or a plate.
Happy planning!