Chop up the pumpkin, potatoes (WITH SKIN ON), onions, leeks, and apples. Sautee them all in a bit of olive oil for a few minutes at the bottom of a LARGE pot. Once they are a bit soft, add vegetable stock until the vegetables are JUST covered. Add a bit of water if necessary. Cover and cook in the same large pot for about one hour. Once the pumpkin and potatoes are all soft, take off heat. Use a slotted spoon to scoop just the vegetables (not the broth) into a blender, and blend completely (it will be nice and thick). Do the blending in batches as necessary. Transfer the blended material into ANOTHER pot or bowl so that the rest of the soup can be blended. Once all of the veggies are blended, add the chicken stock to the thick puree of veggies until they reach a desired consistency for soup. Put the pot back on the stove and add nutmeg, ginger, salt, and pepper to taste. Also add in heavy cream. Heat, stirring occasionally, for at least 15 minutes, and then simmer until it is time to call ESSEN!