1Heat oil in a large (4qt) saucepan and add he chopped onion.Cook over low heat until the onion is translucent and soft, about 10 minutes.
2Remove pan from heat.Stir in flour mixed with small amount of broth(until smooth) ,chicken broth,pumpkin,ginger,salt and pepper.Cover and return to Low heat simmer for 15 minutes DO NOT uncover the pot while pumpkin mixture is cooking or it will bubble and plop all over the stove.(trust me I know ).
If making in advance at this point set the soup aside and only continue with next steps when ready to finish and serve
3Pour in the half&half or light cream and simmer for about 10 minutes.Taste to correct seasoning
4Chill soup thoroughly,at least 2 to 3 hours or over night
5Final step- Serve in very cold chilled bowls.Drop a dollop of whipped cream on top of each serving and sprinkle with nutmeg.