Drain the soaked cashews and transfer them to a blender, adding half a cup of water, the juice of half a lemon, nutritional yeast, salt, and pepper. Blend until smooth and creamy, about 1-2 minutes. Set aside.
Bring a large pot of salted water to a boil. Add your pasta and cook until al dente, about 8-10 minutes. Drain and set aside, saving a cup of pasta water.
While the pasta cooks, heat olive oil in a large skillet over medium heat. Add sliced cremini mushrooms and sauté until they release their juices and turn golden brown, about 5-7 minutes. Add minced garlic and cook until fragrant, about 30 seconds.
Pour the cashew sauce into the skillet with the mushrooms. Stir well and simmer gently over low heat for about 3-5 minutes, until the sauce slightly thickens and flavors meld. Taste and adjust with more lemon juice, salt, or pepper as needed.
Add the cooked pasta to the skillet and toss gently to coat evenly with the sauce. If the sauce is too thick, splash in some reserved pasta water and stir until silky and smooth.
Finish by stirring in chopped fresh herbs and a squeeze of lemon juice. Serve immediately, garnished with extra herbs if desired, for a vibrant, creamy mushroom pasta that’s ready to enjoy.