How to Make It
Put the dried mushrooms in a small bowl and pour the boiling water over them. Soak until softened, about 20 minutes. Remove the mushrooms, reserving the soaking liquid, and chop them. If the liquid is gritty, strain it through a paper-towel-lined sieve.
If using shiitakes or portobellos, remove the stems. Slice the wild mushrooms. In a large frying pan, heat 1 tablespoon of the oil over moderate heat. Add the sliced wild and white mushrooms and the rosemary. Cook, stirring occasionally, until all of the liquid has evaporated, about 5 minutes.
Stir in the remaining 1 tablespoon oil and the onion. Cook, stirring occasionally, until the onion and mushrooms are brown, about 3 minutes longer. Add the garlic and cook 1 minute longer. Stir in the wine, the dried mushrooms with the soaking liquid, and the salt. Simmer until the sauce is slightly thickened, about 5 minutes. Stir in the pepper.
Meanwhile, in a large pot of boiling, salted water, cook the fettuccine until just done, about 12 minutes. Drain. Toss with the mushroom sauce, butter, Parmesan, and parsley. Serve with additional Parmesan.