Preheat oven to 375 degrees F.
To a medium size mixing bowl add mushrooms, olive oil, sea salt, and ground black pepper. Toss to coat. Onto a baking sheet, spread mushrooms in an even layer. Bake 20 minutes, until lightly crisp.
To a medium skillet over medium high heat, add olive oil. When oil is hot, add onions; cook 3-5 minutes, until softened. Add garlic and cook an additional 1-2 minutes.
To a high speed blender, add onions and garlic, silken tofu, water, lemon juice, sea salt, and ground black pepper. Blend on high 2 minutes, until consistency is smooth.
Prepare fettuccine according to package directions. Drain well and toss with sauce mixture.
To serve, top fettuccine with baked shiitake mushrooms and a sprinkling of Italian parsley. Serve warm.