You’ll need a blender or food processor for this sauce, but little else. Here’s how to make a one-ingredient pasta sauce, plus some variations. I’ll include a brief summary for those of you who prefer just a simple overview, and then I’ll provide details for the readers who like a more complete recipe with explanations.
Ingredient: One winter squash.
The quick version: roast a squash and puree it, adding just enough water to make a smooth consistency. (A little pasta cooking water is excellent). Add to hot cooked pasta, stir gently and enjoy!
Variations: stir in grated Parmigiano Reggiano cheese and a little freshly grated nutmeg. Add salt to taste (how much salt you need will depend on the sweetness of the squash you chose, which can only be determined by tasting it). Instead of fresh water, or water left over from cooking the pasta, use chicken stock for a richer sauce. Top the pasta and roasted squash puree with chopped toasted walnuts, or bacon, or roasted prosciutto.
Now for the detailed version:
You can use an acorn squash, butternut squash, or a pumpkin (make sure it’s a pumpkin grown for baking or for use in recipes, not the large inedible ones intended for carving and decorating only) – almost any winter squash except for a spaghetti squash will work. Most grocery stores identify the pumpkins that can be cooked as “pie pumpkins” or “sweet pumpkins”, and they call the others “carving pumpkins” or “Jack-O-Lanterns”. The produce manager can tell you whether the pumpkin is intended for eating or for decorative purposes only.
Line a baking sheet with non-stick foil or parchment paper. You can either cut the squash in half, remove the seeds and lay the squash halves cut-side down on the pan, or you can simply put the whole squash on the pan. There’s some debate as to whether a whole squash should be pierced a couple of times prior to baking. Some cooks say to pierce the squash with a sharp knife or fork, as you would when baking a potato, and some cooks say this allows delicious steam and flavors to escape and they don’t pierce the skin. I’ve roasted whole winter squashes and I simply make one small knife slit in the skin – I don’t feel like using my oven as an experimental pumpkin explosion testing center.
Anyway, roast a winter squash: halved, seeded and cut-side down, or whole. Just roast it until the squash is very tender, when a fork inserted into the squash pierces it easily with no resistance. That will take about 45 minutes to an hour, at 350 degrees, unless you are roasting an unusually large squash, which may take longer.
Let it cool, and then either scrape the flesh from the skin, or cut the whole roasted squash in half and scrape out the seeds and then the flesh. Transfer just the flesh to a blender or food processor. Puree it, and add just enough water to make a smooth sauce. The best choice would be the water left over from cooking pasta: when you drain the pasta just save about a cup of the water. The goal is to have a sauce that is a similar consistency to a cheese sauce, like when you’re making macaroni and cheese, not too thin and watery, and not too thick.
Now you can use the pureed squash as is – just stir it into hot cooked pasta Or you can add some grated parmesan cheese and a little nutmeg (freshly grated nutmeg is best). If the squash was very sweet, you might need some salt, but that’s up to you. You’ll only know how sweet the squash was by tasting it.
I toasted some prosciutto on a baking sheet until the prosciutto was very crispy and crumbled that over the pasta and squash puree just before serving. Crumbled cooked bacon would also be good.
Toasted and chopped walnuts or pecans would also be delicious on this pasta, as would chopped dried cranberries, and/or grated Parmigiano cheese.
But, if you just use the roasted and pureed squash, with a little water added to it to make it a smooth puree, you’ll have a very healthy and simple sauce made from just one real food.