I started out with a 1 ring gas stove, relies on small canisters of gas so I have 11 of those in the shed. (I used roughly 1.5 canisters for 2 nights camping with dd doing a few teas/coffees, bacon breakfast, and dinner).
I also have a mini charcoal bbq (well 2, 1 from mountain warehouse and a slightly better one from Aldi's middle aisle), which are perfect for camping. Because they are charcoal, they can be used to burn ordinary wood if need be (just keep the fire small and controlled).
But my treat to myself was a Kelly Kettle. This is great for boiling water, but as I also got the pot stand, I can put a pot on when the kettle is on it or use the hobo stand part to have a pot when then kettle is not on the fire. It only uses small sticks and pine cones for a small fire, but is remarkably efficient. I have cooked dinner on it in the garden a few times for fun.
At home, we have a gas bbq with a lid, which is very useful for outdoor cooking.
And we also have a log burner that is a narrowing square shape, so I have put a bbq grill on top to cook before...it works but it's very high above the fire to be efficient, and it's not a great design to manage the fire anyway because of the small opening at the top, but that small opening is the reason it can work in an emergency.
Apart from using small pots that transfer heat well (camping type pots or thin cheap ones not the heavy based ones you'd use on the normal cooker), there are other ways to think about cooking.
Skewers or sticks holding chunks or strips of meat, fish, veg, fruit etc.
Tin foil parcels holding smaller pieces or somewhat liquid items (we do mushrooms in butter on bbq at home, or small pieces of fish, carrot, onion and potato together as a meal on camp etc).
Also potatoes wrapped in foil can be put amongst coals to bake with any kind of fire or charcoal bbq.
Look up chocolate cake in an orange to see how to bake an individual cake in an orange peel shell.
And also have a look for things like
Back woods cooking, scout cooking outdoors, camp cooking,for ideas and recipes.
Agree with having a flask for any spare hot water.
And if you have a fire/charcoal bbq (rather than gas), both while it is getting going (so it is lit and going but still flames and not ready to cook food directly on - charcoal coals not yet grey, or wood still burning and not made embers), and once you have finished, put a pot of water on top to heat. (Or other pots where food is sealed away from smoke/flames). To make the most of the fuel while you have it - get it hot for flask and washing up before the fire dies away entirely. (Especially when you have no power).