The root storage has been here long before I came around... Don't know much about it's construction. It works fairly well temperature wise, but it needs to be de-humidified. I learned that the hard way with my potatoes
As for the recipe, I never really measure anything, I've just made it so many times it comes naturally... but I can give you the general process and ingredients:
-Clean, cut and roast one small pumpkin in 1" cubes in a 350 degree oven until soft
-Sautee Mire Poix (Onions, celery, carrots) in Olive Oil until onions are translucent
-Add 3-4 qts Veggie Stock (depending on the size of the pumpkin and amount of mire poix)
-In a Bouquet Garni (Herbs and junk a cheesecloth bag to be removed before blending) add Fresh ginger, bay leaves and cloves
-Bring to a simmer and let reduce for no less than a half hour (I usually let it go until the pumpkin is finished and cooled)
-Remove the Bouquet, Add the pumpkin, Blend until smooth. At this point I often add heavy cream (depending on my audience)
-Salt, pepper, nutmeg and honey to taste (It can take a ton of salt, again play to your audience)
-The version you see the picture of is served in a roasted and hollowed sugar pumpkin and garnished with candied walnuts and creme fraiche.