Cover the porcini mushrooms in cold water and leave to soak for 10 minutes.
Heat 2 tablespoons of olive oil in a large sauté pan, add the pancetta and cook for 5–7 minutes, or until crisp. Add the chilli and garlic and cook for a further 2–3 minutes.
Cook the tagliatelle in a large saucepan of boiling salted water, according to the packet instructions, or until al dente.
Meanwhile, drain the porcini mushrooms, reserving the soaking liquor, and add the porcini to the sauté pan. Strain the soaking liquor into the pan and allow to bubble until reduced by half. Add the tomato and wild mushrooms and cook for 2 minutes. Scatter over the parsley.
Drain the tagliatelle and add to the sauce. Stir in the butter and cheese until the sauce emulsifies.
Divide between four bowls, drizzle with olive oil and serve.