Set a large pot of water to boil and add 2 teaspoons of salt to the pot. Once the water is boiling add the pasta and cook according to the package directions to al dente (set a timer!).
Add the olive oil to a large skillet over medium heat. Once the oil is warm, add the butter.
When the butter is just melted add the diced shallots, red pepper flakes, thyme leaves and sage.
Sautee until the shallots are soft and the herbs are fragrant (1-2 minutes).
Add the halved mushrooms and sautee until the mushrooms are almost cooked through and slightly browned on the outside. They should reduce in size by about half.
Add the champagne to the pan with the mushrooms and let it reduce almost completely, tossing the mushrooms in it white it cooks off.
Reduce the heat to low and add the heavy cream and the parmesan cheese. Stir just until combined and the cheese is melted.
Drain the pasta once it’s cooked to al dente and reserve about ¾ cup of the pasta water.
Add the pasta to the pan with the mushroom mixture and toss everything together, drizzling in the reserved pasta water into the pasta as you toss. Don’t add the whole ¾ cup right away – start with ¼ cup and add a little bit at a time until the sauce reaches a smooth, creamy texture that’s not too thick but still coats the pasta.
Sprinkle more shredded Parmesan over the top and add some more fresh thyme and sage for garnish before serving.
This recipe serves 8 as a side dish and it serves 6 as a main dish.