Scoop out the pumpkin flesh and seeds, reserving them for later.
Slice pumpkin flesh into slices approximately 2 inches thick. Arrange on a baking tray and bake in the centre of the oven for 35 minutes.
Meanwhile, wash and dry the pumpkin seeds throughly and toss in the olive oil and hot chilli powder.
Fry your sage leaves by heating the olive oil over a medium-high flame. Drop the leaves in 6-8 at a time, and fry for few seconds so that they retain their vibrant green colour. Remove the leaves from the hot oil with a slotted spoon and drain on a piece of kitchen paper or clean towel.
Chop the remaining pumpkin guts into pieces, if needed, and add to the baking tray along with the chilli pumpkin seeds.
Roast for a further 10-15 minutes, until the pumpkin is softened and the seeds are golden. Allow to cool completely.
Heat the butter in a large saucepan, and saute the garlic for a minute.
Add the cooled, roasted pumpkin flesh (without the skin), the pumpkin guts and the chicken stock.
Simmer over a medium flame for 10 minutes, leaving the lid off.
Meanwhile, cook the pasta according to the packet instructions and drain.
Puree the pumpkin sauce until smooth and add the grated Parmesan and creme fraiche.
Season well to taste and stir through the hot, cooked pasta.
Serve with the fried sage, chilli pumpkin seeds and extra Parmesan cheese, if desired.
Food waste prevention tip #1: store your leftover Parmesan rinds in the freezer instead of throwing them away. You can add them to soups or sauces, like this one, during the cooking stage and they will melt into the recipe. Food waste prevention tip #2: leftovers of this recipe reheat really well! Store, covered, in the fridge for 2-3 days. When you want to reheat it, add a splash of oil to a saute pan, add your leftover pasta and a few tablespoonfuls of milk. Stir until heated through and enjoy!Food waste prevention tip #3: make the sauce in advance, omitting the Parmesan and creme fraiche, and freeze for later. Defrost, add the cheese and creme fraiche and stir into cooked pasta.