Step 1

In a large pot of boiling salted water, cook pasta until al dente; drain, and return to pot. Set aside. While pasta is cooking, in a small bowl, soak porcini in 1 1/2 cups hot water until tender, at least 15 minutes.

Step 2

Meanwhile, melt 1 tablespoon butter in a large skillet over medium heat. Add shallot; season with salt and pepper. Cook, stirring occasionally, until shallot begins to soften, 3 to 4 minutes. Add wine; cook until almost evaporated, 3 to 5 minutes.

Step 3

Add button and shiitake mushrooms. Cook over medium-high heat, stirring occasionally, until mushrooms are tender and begin to brown, 6 to 8 minutes.

Step 4

Add porcini and their soaking liquid (leaving any grit at the bottom of the bowl) and thyme to skillet. Cook, stirring occasionally, until liquid reduces by half, 2 to 4 minutes. Transfer porcini mixture to pot with pasta. Add Parmesan and remaining butter, and toss to combine. Season with salt and pepper, and serve with more Parmesan.