What I do is this and it works for us, I have children of my own(who eat anything), and often extras, most of which have limited food choices, which I have to tackle,
I/we cook what ever meals we want to cook, regardless of who will be at the table,
I never put food on anyone's plates, I put the food in individual dishes on the table, everything in separate dishes,and separate serving spoons, with a variety of different veg, more washing up, but less threatening it works,
everyone helps themselves, the only rules are don't take too much until you are sure you will eat it, and no one is allowed to say,"I don't like such and such", if they feel that they have to comment they must say, "I haven't learnt to appreciate this yet', because else they are brain washing themselves,
no one comments on others choices,
I find that when children see other children really enjoying and actively competing for items, they forget they don't "like" a food, and try it, if you keep trying a food then your brain recognises it as a food source, and suddenly you like it, my children enjoy the challenge of training their own brain, so keep going at something to they conquer it, they understand how to trick your brain,
I was luck enough to get given about 40 of these bowls, children love the way food looks in them, so I or they chop lots of different things into them, it makes appealing colourful table I don't use the stands,
at five my children were doing a lot of cooking, even if they didn't like what they were cooking, the process of cooking gives them a connection to the food, and when others showed their appreciation, it starts to sink in that there is value to that particular food,
even making a honey dressing,is a very good way to get a child to want to dip salad, one of mine made lots of dressings then suddenly loved smothering stuff in it, they love adding all the ingredients together in a jug, pouring through a funnel and shaking it up in a bottle,
it may be far more hassle to cook with them, but it really pays off, good reading and maths practice as a bonus,
I have in the past, when a child has avoided a individual something, said as I serve myself, "oh,this isn't for you, it's adult only as it so special, you need to have grown up taste", cue begging for a try.
friends are often shocked that their children will be happily eating things at my house they turn their noses up at home, it's because children don't like to miss out, so when surrounded by other children who are competing for something they get drawn in,
one of our teen started eating asparagus and french beans,when he realised the little ones were fighting over the last few pieces, it took a lot of self control not to comment.