M.B.
I have two little boys (4 and 2) who do not eat veggies. I started giving them Odwalla's Original Superfood smoothie. It is green - probably the only green food that I can get them to consume. It's expensive - $7.99 for the big bottle (sometimes Market Basket has it on sale for $4.99) You'll find it in the produce dept. I know lots of people make green smoothies for their kids - I just haven't had any luck with the home made green ones.
I also make them a blended sweet potato and red lentil soup that they love. I can send the recipe if you'd like to try it. Good luck!