1. Preheat the oven to 325°F. Lightly grease (or line with parchment) three baking sheets.

  2. In a large bowl, combine the flours, sesame seeds, sugar, and salt.

  3. Work in the butter then stir in the milk, adding just enough to form a cohesive dough.

  4. Divide the dough into three pieces. Working with one piece at a time, place it on a lightly floured surface (or lightly floured piece of parchment) and roll it ultra-thin, about 1/16".

  5. Sprinkle with a bit of coarse salt, using the rolling pin to press the salt into the dough.

  6. Cut the dough into 1” × 2” rectangles and transfer the crackers to one of the prepared baking sheets. If the crackers are already on parchment, simply pick up the parchment and transfer it to a baking sheet before separating the crackers.

  7. Repeat with the remaining pieces of dough.

  8. Bake the crackers for 20 to 25 minutes, until they begin to brown. Remove them from the oven and cool on a rack.

  9. Store crackers in an airtight container at room temperature up to a week; freeze for longer storage.