Thoughts on making this vegetarian and replacing the parm on top with toasted breadcrumbs

yep, meant vegan

Love this recipe and have made it many, many times. Not clear about your question because this is a vegetarian dish. No meat anywhere. If you mean vegan, the breadcrumbs won't come close to adding the flavor of the parmesan. The cheese gives it a creaminess and a unique flavor. If you do use breadcrumbs, recommend you add more olive oil.

Thanks for pointing to this recipe, it sounds really tempting. As far as I can tell, it is already vegetarian, using no meat. If you wanted to make it vegan, I think you are on track to use breadcrumbs. Toast, perhaps toss with olive oil and finely chopped nut of choice? I think the nut may add the deep umami note that will be missing when there is no Parm. Hey, let us know.