How to make
Boil the mushrooms in salted water. Drain them and grind them to paste. Beat the butter. Add to it the salt, pepper and lemon juice to taste. Beat the mixture well.
The paste is brushed on bread slices. Garnish the sandwiches with lemon slices.
The paste can be prepared with dried mushrooms. They are rinsed, covered with water to bathed, leave to infuse for 3-4 hours and then boil the water in which they were soaked.