Preheat oven to 425 degrees.
Cut the bulb of garlic in half cross-ways. Place on a sheet of heavy foil and drizzle with 1 tablespoon of the olive oil. Replace the top half and wrap tightly. Roast the garlic for 40 minutes and remove from oven. Once garlic has cooled slightly, pop the roasted cloves from both top and bottom halves into a large bowl. Pour any remaining olive oil from the foil into the bowl as well.
Reduce oven temperature to 350 degrees.
Wash and dry the pumpkin. Using a sharp knife, cut the top off the pumpkin, as though you were making a jack-o-lantern, and scoop out the seeds and fibers.
Using the remaining tablespoon of olive oil, rub the inside of the pumpkin all over. Generously salt and pepper and add the fresh nutmeg to the inside of the pumpkin by tilting to sprinkle. Rub so the seasonings are distributed all over. Place inside of a close-fitting parchment-lined baking dish. Set aside.
To the roasted garlic cloves and residual garlic oil, add the shredded Gruyere, cheese curds, the sourdough cubes, herbs de Provence, and another grate or two of fresh nutmeg if desired. Using your fingers, work the roasted garlic into the dry ingredients until evenly distributed.
To the bottom of the inside of the pumpkin, add 1/4 cup of heavy cream. Add the remaining 1/2 cup of cream to the stuffing mixture and stir well. Mixture should be wet but still somewhat crumbly. Spoon the stuffing mixture inside the cavity of the pumpkin.
You may need to press down and pack the pumpkin to fit as much of the stuffing as possible. Do not over-stuff. Replace the top and tent with foil.
Bake at 350 degrees for two hours. Stuffing will expand within the cavity during the bake, so anticipate the pumpkin top to lift from the pumpkin toward the end of the bake, making for an appetizing bubbled-over edge.
Allow the pumpkin to rest on the counter for 10 minutes before carefully transferring to a cutting board. Remove top and cut first in half, then each half into thirds. Serve the baked stuffed pumpkin wedges alongside your traditional Holiday table favorites.