Peel the onion, chop finely and pour over hot water to remove the bitterness. Let stand for 10 minutes, drain the water, and squeeze the onion thoroughly. Pickled onions can also be used. Make a refueling. Mix oil, salt, pepper, lemon balm and garlic powder.
Cut the cheese into small cubes. Champignons, if fresh, peel and wipe with a damp cloth and cut into small slices. (I took canned ones.)
Tear lettuce leaves into small pieces with your hands.