Cut open your pie pumpkin, cut it into large wedges and clean out the seeds and fibers with a spoon. Roast your pumpkin wedges in a moderate oven (180C, 350F) for about 45 minutes, or until the flesh is quite tender when pricked with a fork. (It's fine if the pumpkin browns a bit around the edges but you do not want a lot of caramelization.) Let the pumpkin cool, turning it over to allow any excess liquid to drain out. (If the pumpkin pieces seem watery still, you can wrap them in cheesecloth and squeeze them dry.)

Scrape out the cooked flesh from the pumpkin, leaving the skin behind, into a food processor. Add the amaretti, parmesan and mostarda, and process them until you have a perfectly smooth, stiff paste.

Season the mixture generously with freshly grated nutmeg, fresh ground pepper and salt. If the stuffing mixture is a bit soft or wet, mix in some breadcrumbs, a bit at a time, until the stuffing is stiff and rather dry.

Now it's time to make your egg pasta, in the usual manner. (See this post on making fresh pasta.) Roll the pasta out rather thinly (setting 6—or even thinner if you want—on a pasta roller) since you will be folding the pasta into a double thickness, into long, rather slender sheets.

Place heaping teaspoonfuls of the stuffing about 5 cm (2 in.) apart along the length of your pasta sheet, just off center down the middle of the sheet (as pictured above).

Fold the longer half of the sheet over the stuffing, pressing down with your fingers all around the stuffing to seal the top and bottom layers of pasta together. With a serrated pasta cutter (if you have one, otherwise it's fine to simply use a knife) cut out your tortelli along the three unfolded sides:

For the final touch, you can ensure a tight seal while making your tortelli ever so pretty by pressing down the edges with the prongs of a fork like so:

You should cook your tortelli for a good 5-7 minutes, depending on the thickeness of the dough. They take a bit longer than fresh pasta usually does, because of the double thickness of the pasta and the filling. While the tortelli are cooking, gently melt lots of butter in a small saucepan, adding a sprig of fresh sage if you like to steep along with the butter. (I have read that the sage is not original to the dish, but I like it.) Serve immediately, topped with the melted butter and—if you like—more grated parmesan on top.