Spaghetti squash is a wondrous vegetable, one of our fall favorites. The flesh cooks into long, tender strands like, well, spaghetti, only sweet and earthy-tasting. Cooks sometimes make the mistake of tossing spaghetti squash with robust pasta sauces that obscure the delicate taste. Here, inspired by classic cacio e pepe, we treat it gently, tossing the cooked strands with a simple sauce of minced garlic and shallot warmed in olive oil, black pepper, and freshly grated Parmigiano-Reggiano cheese. Serve this with our Whole Roasted Chicken, Roasted, Herbed Beef Tenderloin, or—for an inspired vegetarian meal—next to Kale and Potato Mash with Romesco Sauce.