1) To make the bread: Place 2 cups of the flour into a bowl or the bucket of a bread machine. Pour the boiling water over the flour, and stir till smooth. Cover the bowl or bucket and set the mixture aside for 30 minutes.
2) In a separate bowl, whisk together the potato flour (or flakes or buds) and the remaining 1 cup of flour with the salt, oil and yeast.
3) Add this to the cooled flour/water mixture, stir, then knead for several minutes (by hand, mixer or bread machine) to form a soft dough. Note: You can allow the dough to go through the entire kneading cycle(s) in the bread machine, but it's not necessary; about a 5-minute knead in the machine, once it gets up to full kneading speed, is fine. The dough should form a ball, but will remain somewhat sticky. Add additional flour only if necessary; if kneading by hand, keep your hands and work surface lightly oiled.
4) Let the dough rise, covered, for 1 hour.
5) Divide the dough into 8 pieces (each about the size of a handball, around 3 ounces), cover, and let rest for 15 to 30 minutes.
6) Roll each piece into a 7"- to 8"-circle, and dry-fry them (fry without oil) over medium heat (about 325°F in an electric frying pan or on an electric griddle) for about 1 minute per side, until they're puffed and flecked with brown spots. Adjust the heat if they seem to be cooking either too quickly, or too slowly; cooking too quickly means they may be raw in the center, while too slowly will dry them out.
7) Transfer the cooked breads to a rack, stacking them to keep them soft. Serve immediately, or cool completely before storing in a plastic bag. Note: If you plan on making these into folded sandwiches, gently fold them in half when you take them off the griddle, rather than laying them flat. That way, they'll retain that folded shape as they cool, and will be easier to make into sandwiches.
8) To make the dressing: Stir together the minced garlic, lemon juice, mustard, minced anchovy, Worcestershire sauce and sour cream. Whisk in the olive oil. Stir in the Parmesan cheese and ground black pepper. You may do all of this in the food processor by processing together the garlic, lemon juice, anchovy or Worcestershire sauce, and sour cream. Drizzle the olive oil through the feed tube with the motor running, then gently pulse in the Parmesan and black pepper. Set the dressing aside. Refrigerate it if you're not going to use it within an hour or so.
9) To make the filling: Grill the chicken and vegetables over medium coals until done (or sauté them in a skillet).
10) Cool, then slice the chicken and cut the vegetables into bite-size pieces.
11) Place a lettuce leaf on each bread. Spoon some of the filling down the center, atop the lettuce. Top with dressing and serve immediately.
Yield: 8 sandwiches.