1. Heat oven to 300 degrees. Line an 8 1/2-by-4 1/2-by-2 1/2-inch loaf pan with parchment paper, and set aside. Using an electric mixer fitted with the whisk attachment, beat the egg whites on high speed, until frothy.

2. While whisking, very slowly add the sugar, and continue whisking until sugar has completely dissolved and the meringue is stiff, about 5 minutes. Fold in flour until combined. Fold in the sesame seeds.

3. Transfer the mixture to the prepared pan, and bake until the meringue is set and lightly browned, 30 to 35 minutes. Remove from oven, turn out bread, and place on a wire rack to cool. When cool, slice as thinly as possible, using a serrated knife. Lay the slices on a parchment-lined baking sheet, return to oven, and bake until slices are lightly browned, 25 to 30 minutes.