9 tablespoons extra-virgin olive oil
Salt and ground black pepper
3 medium unpeeled garlic cloves
1/2 ounce dried porcini mushrooms (rehydrated in 1/2 cup boiling water until softened, about 5 minutes, hydrating liquid strained through damp paper towel–lined sieve and reserved)
1 small shallot, chopped coarse
1 tablespoon fresh thyme leaves
1/4 cup packed parsley leaves, washed and dried thoroughly
1/4 cup finely grated Parmesan
Adjust oven rack to lowest position and heat oven to 450 degrees; line rimmed baking sheet with heavy-duty foil. Toss sliced mushrooms with 2 tablespoons oil and salt and pepper in medium bowl; spread evenly on prepared baking sheet. Roast, stirring occasionally, until browned and crisp, about 25 minutes.
Meanwhile, toast garlic in small dry skillet over medium heat, shaking pan occasionally, until softened and spotty brown, about 8 minutes; when cool, remove anddiscard skins.
In a food processor, process roasted mushrooms, garlic, porcini and liquid, shallot, thyme, parsley and remaining 7 tablespoons oil until smooth, stopping as necessary to scrape down sides of bowl. Transfer mixture to small bowl and stir in cheese; season to taste with salt and pepper.