Tagliatelle with Mushroom Sauce and Walnuts
Cook the pasta in boiling salted water until al dente.
Clean the mushrooms and slice lengthwise. Peel the onion and ginger. Finely chop the onion and thinly slice the ginger.
Heat the oil in a pan. Sauté the onion, ginger, and mushrooms for medium heat for 5 minutes, stirring occasionally.
Drain the pasta and mix with the butter. Mix the broth into the mushroom mixture, and stir in the sour cream. Heat briefly, and season to taste with salt. Transfer the pasta to plates, and top with the mushroom sauce. Garnish with the nuts.