Bring the salted water to the boil, add a dash of vinegar. Then break the eggs into cups and let them slide in slowly. Poach over a low heat for 4 minutes, remove. The eggs can be kept warm in warm water.
Heat the butter in a pan and slowly fry the mushrooms over medium heat, finally season with salt and pepper.
Place 1 egg on each plate and drape the mushrooms over them. Garnish with plenty of chives at the end. The whole thing tastes just as good with a perfectly fried fried egg.