In a large pot, saute leeks, onion and cubes of pumpkin in olive oil for a couple of minutes, stirring so as not to let the oil smoke or crackle.
Add in enough vegetable stock to cover the dry ingredients and bring to a boil. Drop in a piece of parmigiano reggiano rind and a little cracked black pepper. Stir, cover, and reduce heat.
Cook until the pumpkin is super soft, about 25 minutes. Puree, then cook another 15 minutes to reduce out any water and to blend flavors.
During the last 15 minutes of cooking, prepare the garnishes as listed below (Toasted Walnuts and Fried Sage Preparation).
Serve soup hot with garnish.
Toasted Walnuts and Fried Sage Preparation
Toast whole, shelled walnuts under a broiler for a few minutes. Be sure not to burn them!
Rinse and pat dry sage leaves.
Heat olive oil in a deep frying pan.
Fry sage leaves until crispy.
Place sage on a paper towel to absorb oil, sprinkle with salt while still hot.
Slice Ciabatta bread into 1.5 cm thick slices. Toast in the oven until crispy and gently rub with raw garlic clove. (Don't overdo it with the garlic! A quick, gentle rub! Otherwise it will overtake the whole dish!).
Place 2-3 slices of toasted bread in each bowl, then spoon soup into bowl. Now add the garnish: Arrange sage on top of toasted walnuts (the walnuts will act as a raft to keep sage from getting soggy or sinking!).
Additional dash (a mini dash!) of salt and pepper.