Getting a 3 year old to eat vegetables

Any tips? My boy was born big at 9.5# and is taller than most kids his age - ate great as a baby and toddler, including all sorts of vegetables and proteins. Now, aside from dairy, he will only eat proteins - tacos, spaghetti (w/o noodles of course), chicken strips, steak, etc. He drinks a lot of milk and eats fruit and yogurt and takes vitamins. But he gets absolutely zero vegetables. I'm not even talking broccoli and brussel sprouts. We can't get him to eat mashed potatoes and creamed corn. He'll wail and cry at the site of it, and he's never even tried it before.

We've tried not letting him have any other food at all, figuring he'd get hungry - he starved himself out. We've tried taking away all treats and sweets - no ice cream, icees, snowcones, candy, etc. He asked for an icee at the pool today - my wife asked him if he would eat a vegetable with dinner - his reply was "no, I don't want an icee because I'm not going to eat a veggie" (at least he's not old enough to lie).

It's the most illogical thing I've ever seen - if he will eat just 2 bites of a food that isn't really even considered a vegetable anywhere other than Cracker Barrell, I'll buy him anything he wants. He wouldn't trade a bite of peas for eternal happiness or a life of money, hookers, and blow.

Please help - And save me the amateur stuff, like "Oh, let him cook with you and he'll enjoy eating it!" - tried it, thought he was going to start stabbing us with the kitchen knife when we put it near his plate. Or "Hide it in some other foods so he won't notice" - he only eats solid proteins that can't be easily altered. The slightest inconsistency, like minced up zucchini in spaghetti sauce, is found and promptly refused. This is a true illogical aversion that can't be solved.