1. For the dough: In a large bowl or the pan of your bread machine set on the dough cycle, combine the water, yeast, salt, sugar, and sesame oil. Whisk together 1 cup of the flour with the potato flour or potato flakes, and add to the water.

  2. Add the remaining flour and mix until a soft dough forms (or start the bread machine). Adjust the dough's consistency by adding water or flour by the tablespoon as needed. Knead the dough for 6 minutes in a mixer at medium speed, or 8 to 10 minutes by hand. The dough should be soft and smooth, but not stick to your finger when lightly touched.

  3. Cover the mixing bowl or transfer the dough to a greased 8-cup container and let the dough rise for about an hour, until doubled. If using a bread machine, simply let it finish its cycle after checking the consistency.

  4. To make the filling: Mix the tahini, honey, and sesame seeds together until no lumps remain. Stir in the scallions and cilantro.

  5. To shape the rolls: Deflate the dough and roll it out on a lightly floured surface to a 10" x 16" rectangle. Spread the filling over the dough, leaving 1/2" on each of the long sides bare. Roll the dough up from the long side and pinch edges together.

  6. Using a sharp knife or dental floss, slice the dough into 12 pieces. Place the rolls, cut side up, on a parchment-lined baking sheet 1/2" apart. Cover with greased plastic wrap and let rise for 20 minutes while you preheat the oven to 350°F.

  7. Once the rolls have risen enough to look puffy, brush the tops with water and sprinkle with the mixture of black and white sesame seeds. Bake for 20 to 25 minutes, until golden brown. Remove from the oven and serve warm.