Ingredients
2/3 cup sugar
3 large egg whites
1/8 teaspoon salt
1/4 cup (1/2 stick) unsalted butter, melted and cooled
2 tablespoons all-purpose flour
1/2 cup shelled unsalted pistachios, finely chopped in a food processor
Preparation
Preheat oven to 350 degrees. Whisk sugar, egg whites, and salt in a medium bowl until sugar has dissolved. Whisk in butter, then flour. Stir in pistachios.
Line a baking sheet with a nonstick baking mat. Place a long-handled wooden spoon on a clean work surface; prop up each end on a metal spoon to raise it slightly (you will use handle of wooden spoon to form tuiles).
Drop teaspoons of batter onto baking mat, spacing about 2 inches apart; flatten into 1 1/2-inch rounds. Bake until pale golden, 8 to 10 minutes. Let cool on baking sheet 30 seconds.
Working quickly with one cookie at a time, use an offset spatula to lift cookies from sheet and drape them over spoon handle. (If cookies become too crisp to work with, return to oven until pliable, about 1 minute.) Let cookies cool slightly, 20 to 30 seconds, then remove from handle; press sides together to close. Let cool completely. Repeat with remaining batter.
