For a topping there is tuna from John West which comes in handy plastic packs in a range of different flavours
Cooked pasta (fussili or similar shapes not spaghetti) , mixed cold with one of the tuna sachets plus a few olives, halved cherry tomatoes, cucumber, fresh basil/parsley. Carry in a tupperware ( showing my age ). Don't forget a fork or you could whittle one while on the trail