A delightful and company-worthy pasta dish.
Cook the pasta according to package directions.
Place the porcini mushrooms into a heat safe bowl and cover with boiling water. Let sit until the mushrooms are soft, about 20-30 minutes. Drain and reserve the mushroom water. Use a cheesecloth to make sure you get all the grit out of the water. Then chop the porcinis.
In a large pan, heat 1 tablespoon each of butter and olive oil. Add the cremini mushrooms in a single layer and saute until brown on both sides. Do not overcrowd the pan. You will probably have to do this in 2 batches. Remove mushrooms from the pan and reserve.
Add more butter and olive oil to the pan as needed. Saute the garlic, shallot and thyme for 1-2 minutes and then add the porcini mushrooms. Saute until they give off all of their water.
Add 1 cup of the reserved mushroom water and stir. Then add the half and half and cook until it thickens up a bit.
Add the pasta to the sauce and stir well. Add the Parmesan cheese and parsley and stir to combine. Top with more parsley and shaved Parmesan.