To prepare the tagliatelle with cuttlefish and mushrooms, begin by cleaning the porcini: scrape the stems gently with a small paring knife and wipe the caps with a damp paper towel to remove any excess dirt. Avoid washing them under running water. Separate the caps from the stems. Cut the stems into small cubes and slice the caps into thin strips.
Prepare the cuttlefish by separating the tentacles from the body. Finely chop the tentacles and slice the body lengthwise into thin strips. Strip the leaves from a few sprigs of thyme and set aside for finishing.
Heat a generous drizzle of extra virgin olive oil in a large skillet. Add the rosemary sprig and garlic clove, then add the chopped cuttlefish tentacles.
Add the diced porcini stems. Sauté over lively heat for about 5 minutes. Discard the garlic clove and rosemary sprig, then add a generous ladle of warm water and season with salt.
Add the sliced mushroom caps to the pan. Meanwhile, cook the tagliatelle in a large pot of salted boiling water and drain them well al dente, transferring them directly into the skillet with the sauce.
Finish cooking the pasta in the skillet, adding the remaining sliced cuttlefish and a little pasta cooking water as needed to create a glossy sauce. Finish with a drizzle of extra virgin olive oil and the fresh thyme leaves. Serve immediately.
