Thaw the mushrooms and cook them for 15 minutes over moderate heat, place in a colander to drain the water. Wash the vegetables and prepare the remaining necessary ingredients.
Cut the white part of the leek into thin rings, remove the seeds from the bell pepper and cut it into small cubes. Shred the Chinese cabbage into thin strips, and also cut the cucumber into cubes.
Peel the avocado, cut in half and remove the pit, then mash the flesh with a fork until smooth. Add vegetable oil and lemon juice to the resulting mass, mix everything well. In a bowl, mix Chinese cabbage, cucumbers, bell peppers and leeks, add salt to your taste.
Pour vegetable oil into a frying pan and add mushrooms cut into small pieces, fry them over medium heat for 5 minutes.
If you want to impress your guests, then azu with mushrooms and avocado sauce can be served warm. To do this, after frying, immediately mix the mushrooms with the vegetables, pour over the dressing and serve.