I once wrote a blog on this subject. The main rule is: cut everything up before cooking. Saves gas, because it cooks quicker, and the food will not cool down (as it is wont to do if you are eating outdoors) whilst you are cutting it up on the plate - you can just fork or spoon it straight in while it's still hot.
So, basically, just vary stews. If it's really hot out, just chop everything up and put it in a huge bowl, mix it all together and eat it as a salad with some crusty bread.
In both cases, one knife, one board, one saucepan or bowl should be all that is required.
A pressure cooker is a marvellous thing to have with you. Also saves gas!
My mother's camping speciality was "Pot mess". My cousins loved it, and it really was quick and easy. Just tins of veg, tomatoes (for the juice) and corned beef. Maybe start off with cubed potatoes, fry them for a bit, then empty the tins into the pot.
For the first day, I prepared a large stew some days before, and froze it. It defrosted on the journey and, what with pitching tents, connecting up gas cookers and pumping up mattresses, we could sit down to eat as soon as we were finished, as it was a ready meal with no preparation necessary, just needed heating up.