Have you tried or heard of this soup?
Sounds really yummy. FWIW I don't think the chef was rude for not disclosing his recipe - presumably it's his creation and he's entitled not to tell other people how to copy it!
Anyway, I think you could make something similar fairly easily. I'd roast the parsnips in olive oil and S&P, maybe a little nutmeg or ginger. Then mash 'em and blend with veggie stock and/or cream, and stir in some blue cheese near the end.