Roasted Pumpkin Pasta with Parmesan Garlic Cream Sauce

2 Preheat the oven to 400 degrees.
0 If using a whole squash, peel it, remove the seeds and slice into 1-inch chunks. 
4 Combine the squash and [wprm-ingredient text="¼ cup finely chopped onion" uid="2"] on a large rimmed baking sheet. Toss with [wprm-ingredient text="¼ cup extra-virgin olive oil" uid="4"], 1 teaspoon salt and 10 or 12 grinds of black pepper. Cover the pan with aluminum foil and bake 25 minutes. Remove the foil and stir the squash around with a spatula. Roast 15 minutes more, or until the squash is tender and lightly browned.
6 Make the sauce: Pour [wprm-ingredient text="1½ cups heavy whipping cream" uid="8"] into a saucepan. Drop in [wprm-ingredient text="4 whole garlic cloves" uid="10"] and thyme sprigs and bring to a simmer — lower the heat and watch that it doesn't boil over. Simmer 20 minutes, until the cream is slightly reduced and the garlic is soft. Remove from the heat and steep 10 minutes, then remove the garlic and thyme. Stir in ½ teaspoon salt and ½ cup of the Parmesan cheese. Transfer the sauce to a serving bowl with the butter and keep warm.
8 Bring a 6 quart pot of water to a boil with 2 tablespoons kosher salt. Cook the pasta until al dente. Drain and add to the bowl with the sauce.
10 Add the squash and [wprm-ingredient text="1½ cups baby kale or spinach leaves" uid="20"] to the bowl and gently stir everything together until evenly coated with the sauce. Serve with the remaining cheese and chopped thyme sprinkled over the top.