Preheat oven to 375F.
To peel pumpkin, cut in half then scoop out seeds. Cut into wedges and carve flesh away from skin and chop into small bite-sized pieces.
For the butternut squash, cut in half across, separating the upper half from the bulbous bottom. Then, use a sharp vegetable peeler or pairing knife to trim away skin. Cut off top stem and chop into bite-sized pieces. Halve bulbous end, seed and chop.
Lightly dress pumpkin or squash in EVOO, salt, pepper and nutmeg.
Arrange pieces on a baking sheet or cooling rack set over baking sheet. Roast 35-40 minutes, until very tender. Toast the pumpkin seeds and nuts in the oven the last few minutes of roasting time.
Pure half the squash or pumpkin in a food processor until smooth; reserve the remainder in dish.
Meanwhile, combine stock and water and saffron threads in a saucepot. Bring to boil then reduce heat to low and keep liquids warm.
In a round-bottomed pan or skillet heat EVOO, 2 turns of the pan over medium-high heat. Add garlic and onions and soften a few minutes. Stir in Arborio and toast a minute or 2, add wine and let it absorb completely. Add saffron stock in small batches of a few ladles at a time, stirring a minute or 2 for each addition of stock. Cook the liquids out and continue to add more a ladle or two at a time for 18 minutes. Stir in butter, cheese and pure of squash or pumpkin. Serve in shallow bowls topped with pieces of roasted squash, seeds, nuts and herbs.