Rehydrate the Porcini Mushrooms:

• Soak the dried porcini mushrooms in the hot water for 1 hour.
• Remove the soaked mushrooms from the water and squeeze to drain well. Reserve the soaking liquid.
• Finely chop the drained porcini and set aside.

Prepare the Pasta:

• Put a large pot of salted water on to boil.

Cook the Onion and Garlic:

• Heat the virgin olive oil in a large skillet over medium-low heat, add the onion and sauté for 5 minutes until soft.
• Add the garlic, stir for 30 seconds, and then add the butter.

Cook the Mushrooms:

• Increase the heat to medium and add the sliced portobello mushrooms, gently stirring for 4-5 minutes.
• Add the chopped porcini, marsala wine, and reserved porcini liquid. Bring to the boil and allow to simmer for a couple of minutes.
• Turn off heat and set aside.

Cook the Pasta:

• Once the water is boiling, add the fettuccine and cook according to the package instructions until al dente.
• Drain the pasta well.

Combine Pasta and Mushroom Mixture:

• Add the drained pasta to the mushroom mixture along with half of the parsley and some finely grated Pecorino cheese. Mix well.

Serve:

• Serve on individual plates or one large platter.
• Sprinkle over the remaining parsley, more grated Pecorino, and a good drizzle of virgin olive oil.
• Finally, shave or finely grate the black truffle over the top.