To make the pistou sauce: Place all the pistou ingredients in a food processor and process until finely chopped. Season to taste with salt and pepper.
Cook linguine per package directions; drain and reserve 2 tbs of the pasta water.
In a wok or deep frying pan, melt the butter over high heat and add the mushrooms, stirring to prevent burning. Cover and cook for 3 minutes. Remove lid and cook over the high heat until the liquid is evaporated and mushrooms are golden brown. Remove from the pan and set aside.
Add the pistou sauce to the pan and bring to a boil. Then add the pasta and reserved water. Toss to combine. Add salt and pepper to taste.
Add the Parmesan and the mushrooms and toss. Serve immediately.
See post for copycat versions of creme fraiche and a substitute.