Place mushrooms in a medium sized bowl and cover with 2 cups of water. Soak for 20 minutes. Drain reserving the liquid.
Heat olive oil on in a large sautee pan on medium heat and add the garlic. Remove the garlic and discard. Add the mushrooms and cook for about 4 minutes until they are soft. Increase the temperature to high and add the wine and sage. Cook until the alcohol evaporates- about 3 minutes.
Add the broth, 1 cup of the reserved mushroom water and the salt. Cook until he liquid is reduced in half- about 10-15 minutes.
In a large pot of boiling, salted water, cook the fettucini until just done. Drain and toss with the mushroom mixture.