Cut the top (one third) of your pumpkin to create a lid for your pumpkin serving bowl. Scoop out the seeds and strings, cleaning the inside well of any debris. Clean the seeds and place them on a cookie sheet. Sprinkle the seeds with a little salt. Roast in a 200°F oven until lightly golden brown. Set them aside to be used as a garnish.
2 ½ cups of fresh pumpkin can be cooked on the stove top or baked for a stronger taste. Pre-heat oven to 350 degrees or boil a pot of water. Cut up a large pumpkin into small pieces that will fit in a baking dish. Remove the strings and debris with a large spoon. Place pumpkin upside down (peel should be up) in the baking dish - the baking dish should have sides that come up at least 2 inches. Once you have the pumpkin in the baking dish, add an inch of water to steam the pumpkin in the oven. Bake or boil until tender (approximately 45 to 60 minutes depending on the size of the pumpkin.
Remove the pumpkin from the water/baking dish and let cool. Scoop out and measure 2 ½ cups of pumpkin into freezer bags and store. The pumpkin is good for a year in the freezer.
In a large soup pot, melt 2 tbsp of butter over a medium heat. Sauté onion, celery and garlic for about 10 minutes. Add the pumpkin, sherry and chicken broth. Blend in well with a whisk. Add the thyme sprig. Simmer for an additional 20 minutes. Remove thyme sprig. Remove the mixture from the heat and puree in a blender. Be careful to puree small amounts of the hot mixture with the blender top on to avoid having the mixture burst out of the blender. Alternatively, if you like it a bit more substantial, mash with a large fork or potato masher. Return the mixture to the pot. Melt the remaining 2 tbsp of butter in a separate sauce pan. Whisk in 2 tbsp of flour. Whisk in the cream. Blend well. Cook for one minute. Whisk the flour, butter and cream mixture into pumpkin puree. Simmer for 5 minutes more.
Heat the pumpkin shell in a 200ºF oven for 10 to 15 minutes before adding soup to keep the soup warm for a longer period of time. Pour soup into your hollowed-out pumpkin serving bowl. Serve the toasted pumpkin seeds on the side for garnish and plenty of fresh cracked pepper.