If he likes baked fries made with potato maybe try th same with other veg. We could have 'chips' every night of the week and still be healthy because I used a range of veg. DS knows what they are and each time I introduced a new one I put it separately on his plate and told him what it was, "this is a sweet potato chip, it's like a chip", "this is a celeriac chip, it's another type of chip". I actually use just a small amount of white potato as other veg offer more in the way of vits etc. So, sweet pot is a good one to start as it is so sweet and the edges caramelize making it even sweeter which is appealing to kids and adults!
parsnip
carrot
celeriac
turnip
swede
butternut squash (although much less chip/fry like because of the shape)
I often toss them in a small amount of oil then season with garlic powder or dried herbs, rosemary for instance. We all eat them and my family now don't bat an eye when they are given 'chips' and they are a variety of flavours. I usually let DS have a bit of tom ketchup or mayo for dipping in too as that's fun.
Otherwise I'd just steam veg and serve them plain so he can see them, name them and try them with or without a bit of dip.
baby corn
carrot batons
asparagus
long stem brocholi (dinosaur trees)
green beans
mange tout
sugar snap peas
These are all things which take very little prep and just throw in the steamer.
When I make a stew I pick out all the veg and put them in their own little pile on DS's plate then take care to point at and name each item so he knows what it is. have never hidden anything, he wouldn't go for it anyway. When he was younger even a carrot chopped in a different shape (eg circles instead of batons) would be questioned, he ate a huge variety of food but had to know exactly what each thing was and for it not to be mixed up (loved the added flavour of veg cooked in stew but couldn't have eaten it all mixed up iyswim)
I'm not big on doing cute food but I do occasionally make a face, or alien, or other kind of picture out of food as I serve it DS. He loves it just for the fun of it. Today I made a sandwich cut in half as a truck with front cab, and strips of red pepper 'logs' piled in the back, cherry tom wheels, cucumber truck panels and driver window.
Mine has also loved counting related food like 1 tom, 2 carrot batons, 3 green beans, 4 quarters of sliced cucumber etc or kidney beans in a line which he can count down as he eats them one by one.