If they don't like some of the veg that are in any recipes they want to try, why not try blitzing them so they don't notice them? Or mix them in with mash potato?
It's kind of like what some mum's have done with meals for years so their kids get the 'goodness' of the veg, just without realising it
Hopefully they can find something they like, and ways around the veg, but like the others have said, veg is a big part of SW, and althought they can eat fruit too, fruit has sugars in so too much of it can be detrimental to the weight losses.