For roasting veggies try lining the baking sheet with parchment paper to keep the veggies from sticking. Balsamic vinegars can add some nice flavor and help any herbs you might want to add stick. Only bake until veggies are cooked through. Any longer and they will dry out.
I haven’t tried this method but I’ve had good luck with other recipes from this site. Let me know if you try it. https://minimalistbaker.com/oil-free-roasted-vegetables/