5yo boy, a fairly classic case of fussy small child beige eating preferences. The only vegetables he knowingly eats is cucumber, tomatoes and olives. He has some other vegetables hidden - grated up carrot and courgette in bolognaise sauce. He's quite sensitive to smells of things, and if he thinks a smell is "yucky" it will make him gag and be sick. He always had a hair trigger gag reflex for things like bits of tomato skin getting caught at the back of his throat or taking an overly large bite of something, instant vomit. If he smells something like cat food that he doesn't like, boom, is sick.
He has taken to saying that even the sight/smell of vegetables on other peoples' plates is yucky. If he comes to the table and sees e.g. broccoli on another plate, even raw carrot in a bowl on the opposite side of the table, he refuses to sit at the table, cries that it's yucky, and presumably if "forced" to sit there would pretty quickly work himself into being sick. So he eats his dinner on the sofa.
Wondering how to try to work through this, as anything that results in him being sat at the table with other people but then vomiting is clearly not a win, but it's getting quite awkward to try to work around. We've tried things like building a cardboard wall so he can't see it, but he still says he can smell it and gets upset. Even when it's something that doesn't have a strong smell, like raw carrot sticks. Notably if he's distracted and engrossed by something else, he doesn't usually notice it's even there. So it's consciously seeing a vegetable and then deciding he can smell it and it's yucky that's the issue.