So, I was reading how it'll be illegal to name a 'Cornish Pasty' made outside of Cornwall and I was thinking...
What is your favourite authentic 'campaign food'. You know, food that you make using time-accurate ingredients, that you actually enjoy. My personal is 'soldiers porridge', which I'll be dining on tomorrow, I'm sure;
Pop 500g oats in a reasonably big pot. Enough goats-milk & water (half and half) to make them very wet. Throw in chunks of your favourite dried meat. (I'm partial to Martin's finest Wine+Pepper, myself). Bring to a low-boil for 20 mins. When the meat feels like it's softening up, throw in two or three leeks, chopped up in big rings. They will reduce and lovely & sweet. Leave it on the heat for another 10 mins, check is the meat soft and are the leeks well cooked. Throw in a knob of hard cheese at the very end, for flavour.