Well, breakfast is easy if you like pancakes ( eggs, flour, milk, sugar, butter and honey for topping ) - I'll link a easy recipe as well. You could also make oatmeal with stewed fruit ( made from a bag of dried fruit like apricots etc ) which would only require dried fruit, sugar, oatmeal and milk.

Lunches I think a home made soup is good - grab a bag of vegetables like carrots potatoes etc that you will use for the three days and make a soup, serve with bread rolls. Use dried peas and dried/tinned vegetables to make it easier if you like. If you make a big batch the one dish will last a few days so its already made for the rest of the holiday. You could always make pumpkin soup with a big fat pumpkin and some cream/milk and a few spices....it doesn't have to be complicated...

Dinners you can't go past wholesome dishes like garlic cheese potatoes or chilli stew of some kind with lots of beans and bacon and ground beef - again if you make up a big dish it will last for a few days. You really only need onions, meat, potatoes, beans and spices. If you bring enough bacon you can use it for breakfast too :)

I used to make spinach pies to take away on our short breaks - all ready made and easy for lunch or dinner so if you have a favorite pie make it ahead of time and bring it along if you can....

I hope this helps, not sure what you like to eat :)