Creamy mushroom egg yolk pasta

Method

1.  Bring a large pan of salted water to the boil. Put the porcini in a small bowl and cover with 50ml just-boiled water from the kettle. Set aside to soak for
   10 minutes. Meanwhile, heat a large, dry frying pan over a high heat. Add the fresh mushrooms in a single layer (you’ll probably need to do this in 2 batches), cook for a few minutes, then turn and cook for few minutes more until golden-brown and the moisture has evaporated (see Be A Better Cook). Tip onto a plate.
2. While the fresh mushrooms cook, add the pasta to the boiling water and cook for 1-2 minutes less than the packet instructions.
3. Return the cooked mushrooms to the pan over a medium heat and stir in the butter and garlic. Cook for a minute, stirring, tip in the porcini mushrooms and liquid, then stir in the crème fraîche.
4. Drain the pasta, reserving a cupful of pasta water, then tip the tagliatelle into the mushroom pan. Stir quickly to combine and coat the pasta, adding splashes of the cooking water as needed to help create a smooth rather than claggy sauce. Season to taste with salt and pepper, then divide between 2 plates. Carefully top each one with an intact egg yolk and some chives. Serve straightaway so the yolk can be stirred into the hot pasta and sauce.