Tasty nibbles

Ok, when the Dr said to keep R's diet plain so that if he reacts again we'll have a chance of knowing what it is too, I thought that would be quite easy. 
I make most of our dinners myself, this week we have had, jacket potatoes, stew, chilli, stuffed peppers and gammon and chips.  Even deserts aren't too much of a problem, we don't have them every day but I quite like baking (see my Bakewell tart post earlier on) but I'm struggling for ideas for tasty nibbles, things for lunchboxes in particular, R often has the same thing in his lunch box, typically:

                      a sandwich or Thin (GF) with ham or tuna mayo (home-made)
                      free from chocolate brownie from Tesco,
                      cucumber and or cherry tomatoes,
                      a fruit string/school bar/fruit
                      and a yoghurt/frube
                      with a drink.

I had (just before his reaction) bought some animal biscuits from Australia via Freego.com, but he didn't like them.  He will take fruit, for instance today I sent in tinned peaches (I did open them for him and put some in a tub lol), but it's the change from the free from chocolate brownie I'm after really, we're going to have a go at making GF flapjack using his GF porridge oats this weekend, but I need more easy and cheap ideas that he's going to like, they don't have to be overly healthy as he has plenty of healthy options to take from salad items and fruit as he eats lots of those.

I'd love your suggestions :)