Pour 1/4 litre of boiling water over the porcini and leave to soak. In the meantime clean, wash and thinly slice the zucchini and mushrooms. Peel garlic and press it through the press.
Fry vegetables and garlic in hot fat for about 5 minutes and season with salt and pepper. Add porcini mushrooms in soaking water and cream and bring to the boil. Sprinkle in sauce thickener. Season again with salt and pepper, lemon juice and thyme leaves.
Cook the pasta in boiling salted water for about 1 minute, drain and serve with the mushroom sauce. Serve garnished with lemon and thyme.