Preheat the oven to 400 degrees F. Prepare the Pumpkin Puree: In a small baking tray, combine the pumpkin chunks with the water. Cover and bake until tender, about 1 hour. Drain excess water. Scoop out the flesh of the chunks of pumpkin, transfer to a bowl, and mash. Stir in the remaining ingredients and mix well.
Puree in a food mill and correct seasonings, to taste. Keep warm over simmering water, stirring when ready to serve.
Prepare the Piccata: Place 1 sage leaf in the center of each slice of turkey and season with pepper. Top with a slice of prosciutto and press together with the palm of your hand. Season the other side with salt and pepper and dust both sides lightly with flour.
Heat a large, heavy saute pan and add the vegetable oil. Sear the turkey scallops, prosciutto-side down, until golden. Turn and sear the other side. As the turkey scallops are cooked, remove from the pan and keep warm. Pour out the oil, add the chopped sage, and deglaze the pan with the port. Add stock and lemon juice and reduce by half. Whisk in the butter and keep warm.
Divide the pumpkin puree and mound in the center of each of 4 warm plates. Surround with 3 turkey scallops and spoon a little of the sauce over. Serve with Cranberry Catsup.
In a medium stainless steel or enamel saucepan, combine all of the ingredients. Cook over a low flame, stirring often, until thick and almost smooth, 25 to 30 minutes. There is very little liquid, so you must be careful of scorching. Strain through a food mill. Cool and refrigerate in a covered container until needed.
Recipe courtesy Wolfgang Puck, "Adventures in the Kitchen," Random House, 1991