Step 1: In a large pot, boil water and cook pasta, and in the mean time cook the mushroom combination. Time it so that the pasta is ready when the mushrooms are.
Step 2: In a large skillet, over medium heat sauté the onion and shallots until they begin to caramelize, about 15 minutes, stirring from time to time. Add the chanterelles and cook them until the reduce in size, about 10 minutes. Season with salt and pepper.
Step 3: Stir in sour cream and take off the heat. Serve over pasta with a dollop of fresh ricotta.