Use these pickled mushrooms to make chef Daniel Humm's Loup de Mer.
In a medium saucepan, combine 1 3/4 cups water with vinegar. Add salt; stir to dissolve. Place saucepan over medium heat and bring to a simmer.
Place mushrooms in a medium heatproof bowl; pour 1 cup liquid over mushrooms and let stand until cooled to room temperature; reserve remaining liquid for another use. Transfer mushrooms and their liquid to an airtight container and keep refrigerated until ready to use, up to 1 week. Drain from liquid and dry with a paper towel before using.