Very easy and very nice.
Dry fry the Cs (all curries are mostly made with spices that start with C … seriously), then grind them. In the meantime, or after, fry thinly sliced onions + ginger in olive oil. Once they’re slightly browned, add the spices (including garam masala) and some butter. Fry/stir for a little longer (maybe a couple of minutes). Add the diced parsnips and coat them, then add milk and chicken stock (1:2 ratio) to cover. Boil for about 30 mins, til the parsnips are somewhat soft, then blitz. You probably need some salt, too.
That gives a basic recipe. I added sliced grilled sausages.
I think shredded roast duck legs would also go well, but I haven’t tried yet.
Chilli, either fresh (which would look nice added at the end) or ground, would be good, too, but not necessary.