Preheat the oven to 350 degrees F.

Using an electric mixer, cream the butter and sugar together until light and fluffy. While continuing to mix, slowly add the egg whites until evenly mixed, then add the flour little by little until thoroughly combined. Add the sesame seeds and salt and mix well.

Line a large baking sheet with a silicone sheet. Using a rectangular template, place a thin layer of the tuile batter onto the sheet in a rectangle shape, remove the template, and repeat, fitting as many on the baking sheet as you can. Bake until the tuiles are golden and evenly browned, about 10 minutes. Remove the tuiles from the oven and, working quickly, remove them from the baking sheet (one at a time) and pinch the two short ends together to form a ring shape. If you don’t work quickly enough, the tuiles will become stiff and difficult to bend. Set aside to dry in a cool place until ready to serve the tartare.