Lay mushrooms on sheets of paper towels; cover with clean, damp kitchen towels. Thinly slice celery, and transfer to a bowl; cover with plastic. Refrigerate.
Stir together lemon juice and shallot. Let stand at least 15 minutes or up to 2 hours. Whisk in oil until emulsified, and season with salt and pepper. Toss mushrooms and celery with dressing; let stand 10 minutes. Divide lettuce among places, and top with mushroom mixture. Shave cheese with a vegetable peeler over tops.
Mushroom lovers or committed veggies...this is a delicious recipe...flavor n texture. Personal comment...I don't like the "string" of each celery stalk. Now I peel...like we all peel potatoes. Regardless...this recipe makes delicious food.
Annie, Fremont, CA