This simple Portabello Mushroom Pasta is made with a rich mushroom & thyme ragù. The sauce is a base of shallots, tomato paste, thyme and garlic. A splash of balsamic vinegar brings out the deep and rich tomato flavors in this mushroom sauce.
Bring a large pot of water to a boil and then add 2 tablespoons kosher salt. This salt will flavor the noodles. Cook the pasta until al dente. Scoop out and RESERVE 1/2 cup of the pasta water, then drain the pasta.
While your pasta is cooking, heat olive oil in a large skillet over medium heat. Once warm, add shallots and a pinch of Kosher salt and pepper. Sauté, stirring frequently, until the shallots are softened, but not browned.
Add the mushrooms to the pan. Cook the mushrooms for a few minutes until they start to soften and darken in color. Stir in 1/2 teaspoon Kosher salt. Continue cooking until the mushrooms become tender and their liquid evaporates.
Add the garlic, thyme, chili flakes, tomato paste, balsamic vinegar and butter to the mushrooms. Cook for 1 minute.
Add the 1/3 cup of pasta water and stir over medium heat until the mixture becomes saucy. Add the cooked pasta to the pan and toss gently with tongs to coat with the sauce, adding more pasta water if it's too dry. Taste for seasoning.
Add grated Parmigiano cheese over the pasta and serve.