I make veggie chips for my fussy nieces - just slice lengthways with a potato peeler in thin slices , sweet potato, parsnip, carrot and beetroot - put on baking tray in 180 oven with a spray of olive oil and you have chips!
Does he like fried rice? Or corn on the cob? Or raw carrot or cucumber sticks as dippers for tzatiki or guacamole? or my DS loves fresh raw peas as an afternoon snack - maybe don't always make them
em part of dinner as he will expect that?
Also it's easy to add a bunch of baby spinach leaves to a berry smoothie , the red/purple colour of the berries hides the green