Creamy Mushroom Pasta Sauce with Crème Fraîche

0 Prepare the mushrooms: Trim the stems off [wprm-ingredient text="1½ pounds white button or cremini mushrooms" uid="0"]s. Tear the caps into generous bite-sized pieces - you want a rustic, chunky texture.
1 Bring a large (5-6 quarts) water to a boil along with 4 tablespoons kosher salt (or use 1 ½ tablespoons regular table salt). Cook [wprm-ingredient text="½ pound fettuccine or linguine pasta" uid="2"] according to package directions, until al dente. Before draining the pasta, scoop out 1 cup of the cooking water and reserve.
2 While the pasta cooks, heat [wprm-ingredient text="3 tablespoons extra virgin olive oil" uid="3"] in a large (12-inch) skillet (preferably nonstick) over medium-high heat. Add the mushrooms to the pan and spread them out in one layer. Cook 5 minutes without stirring. Give the pan a shake and stir the mushrooms around. Cook another 5 minutes.
3 At this point, the mushrooms should be taking on some color and releasing some liquid. Add 1 teaspoon salt, [wprm-ingredient text="¼ cup finely chopped shallot" uid="4"], [wprm-ingredient text="1 tablespoon minced garlic" uid="5"], [wprm-ingredient text="1 tablespoon chopped fresh thyme" uid="6"] and [wprm-ingredient text="¼ teaspoon crushed red chili flakes" uid="7"] and stir well. Cook until the shallots are softened, about 2 minutes.
4 Add [wprm-ingredient text="¾ cup creme fraiche or heavy cream" uid="9"] and [wprm-ingredient text="1 tablespoon chopped fresh parsley" uid="10"] to the mushrooms. Gently simmer until the sauce thickens. Add ⅓ cup of the reserved water and [wprm-ingredient text="2 teaspoons fresh lemon juice" uid="8"] and stir, scraping the pan to release any browned bits.
5 Put the cooked pasta in the pan and use tongs to toss in the sauce. Add a bit more pasta water if the sauce seems dry. Remove from the heat, sprinkle with  [wprm-ingredient text="¼ cup freshly grated Parmesan cheese" uid="11"] and serve.