In a casserole type pan stir the pancetta for 3-4 minutes. Add the onion and garlic and stir for 2-3 minutes until they get translucent. Put the mushrooms and leave the food liquid reduce. Pour the wine and wait until the alcohol evaporates. Add the tomatoes and herbs, season with salt and pepper and boil for 15-20 minutes until the sauce becomes thick. Bring a large casserole of salted water to the boil, cook the tagliatelle for 5 minutes and transfer them immediately to the pan with the mushrooms and pancetta sauce. In this way their cooking water will loosen the sauce to a nice silky consistency. Remove from heat and add the yoghurt and cheese. Mix everything well and serve straight away.