I wouldnt take a random recipe from google, the majority of recipes on the net are written by people who have no idea. Use a chef website to get decent ones. www.chef2chef.net is good.
As for the soup, roast chunks of pumpkin brushed with oil (or olive oil), salt & pepper. When it's turned a good colour pour some honey on it and roast for another half an hour.
Cook some onions in butter on med heat and add some dried herbs if you want. Adding dried herbs (rosemary, thyme or sage) at the beginning is always better than at the end.
Add the roasted pumpkin, salt & pepper and then add not-too-concentrated hot chicken or veg stock. Blend well, adding a little cream.
When in each bowl drizzle some olive oil around and garnish with nuts. Cashew or peanuts crushed and mixed with s&p & olive oil is good. A swirl of creme fraiche is good too. The peanut butter idea sounds good, you'd probably put it in when you add the pumpkin to the pan. Madras curry powder also goes well with root veg.