I roast my veg first, it tastes waaaaaaaay better.
And retain nutrients too i'd think.

I can't believe i never thought to do it this way...i've just always followed my mother-in-law's recipe from 13years ago when i first made it (i can't actually remember ever having pumpkin soup at home- probably because if we ever had soup it would always be dad's split pea, bacon bone and every vegetable he could find- all done in a pressure cooker).