Cheese and yogurts causes major problems for me and so would anything with garlic or spices, vinegars, dressings or pickles, I also have to avoid yeast and I am avoiding meat, fish and eggs because they are hard to digest and cause toxic overload in my liver (though I am not vegan by choice and I do miss meat and fishes very much).
If I were having a picnic (which I very often do!) I would pack a lovely risotto in a tub with an unusual grain such as Barley, Quinoa, Amaranth, lovely rice etc... In that I would use lentils, mung beans or black beans, possible a few mixed nuts and seeds and raisins (although I keep them to a minimum because they are hard to digest), I would also have mixed vegetables like parsnips, cucumber, celery, courgette, avocado, would also have alfalfa sprouts etc... Might also include lovely fresh herbs like parsley or basil (but not coriander, this seems to bring on horrid pain and symptoms) Would then drizzle a tablespoon of lovely oil such as olive, hemp, avocado or ghee etc...
Desert would probably be a millionaire shortbread, flapjack or very dark rich chocolate, fruit cake (anything sweet really!)
Enjoy! xxx