Preheat the oven to 200ºC / 400ºF / Gas Mark 6. Stir the fontina cheese into the Bechamel Sauce
Melt 25g / 1 oz of the butter in a large saucepan. Add the mushrooms and cook over a low heat,
stirring occasionally for 10 minutes.
Meanwhile bring a large saucepan of lightly salted water to the boil. Add the pasta return to
the boil and cook for 8-10 minutes or until tender but still firm to the bite. Drain, return to the
saucepan and add the remaining butter, the egg yolks and about one-third of the sauce, then season
to taste with salt and pepper. Toss well to mix then gently stir in the mushrooms.
Lightly grease a large oven proof dish with butter and spoon in the pasta mixture. Pour over the
remaining sauce evenly and sprinkle with the grated pecorino cheese. Bake in the preheated oven for
15-20 minutes. or until golden brown. Serve immediately with mixed salad leaves.