Sometimes our food aversions have to do with that 'one back experience' with an item (e.g. for me ... sour cream, dairy allergy, and Taco Time that one time ... resulting in 20+ years of avoidance) ... especially bad preparation.
Anyway, on the veggie side of things: oven-roasted or microwave steamed are good, nutritious ways to eat them, the former being tastier (when a little bit of olive oil and salt is added, along with some spices), the latter a bit more nutritious (if you're not losing water-soluble vitamins to water but not using extra water ...). Cauliflower florets, lightly oiled, at about 400F for almost an hour? Yum.
Going vegetarian, then, is easy enough if you get good protein sources, and legumes are a good start. Lentils are nice. Combine with grains, especially brown rice. If you like risotto, swap out the short-grain white rice for barley, cook in a little vegetable broth, add parmesan (if lacto-ovo, not vegan).
Smooth vegetable soups? Good use for a food processor. Thinly sliced cucumbers with red onion and tomato along with a vinaigrette make a great salad.
My picky-eater of an SO loves roasted veggies and the soups. Not hot on barley.