We can't have our cake and eat it, so to speak. Go to dietdoctor.com and see all the veggies you
can have. If you don't like lettuce don't eat it
Surely there must be some above ground veggies you like? Also consider that your preference for starchy root veggies could be down to carb dependence, the very thing we're trying to escape, and that there are a zillion ways of preparing veggies. Have a look at recipes on dietdoctor.com. They're very inspirational. Yes, I miss my spuds too, mash, roasted, whatever, but hey, that's life - literally speaking.