Pasta with a Creamy Mushroom Sauce - Ren Behan Knob Butter 200g Mushrooms button, dried porcini Splash Wine 150ml Double Cream Twist Black Pepper While the pasta is cooking, melt a knob of butter in a frying pan and add the chopped mushrooms. Cook them gently, stirring, for five minutes. Add a splash wine, a couple of tablespoons of the pasta water and cook for a further minute. Pour in the double cream and cook for another minute, stirring. Grind in a twist of black pepper.