Frozen meals, if I cook a stir fry, stew etc at home I'll freeze it in a plastic tub and take it fishing with me, put it in a sauce pan on really low heat and raise the heat once its not a solid block anymore, maybe and a teaspoon of water.
if not, cups of tea and biscuits as snacks, Poridge for breakfast and pot noodle for dinner.
I used to cook proper meals on the bank but the washing up drove me mad lol