This is the crust from the Rosemary & Prosciutto Stromboli recipe in The Healing Kitchen, by Alaena Haber & Sarah Ballantyne. I use it to make a flexible flatbread crust.

1 cup of cooked and mashed white sweet potato (about 1 medium)
1/2 cup tapioca starch
1/4 tsp fine sea salt
1 tsp finely chopped fresh rosemary
1 Tbsp bacon fat (to brush on the crust while baking), or another fat of your choice

• Preheat oven to 375°F.
• Line a rimmed baking sheet with parchment paper.
• In a food processor, combine the mashed sweet potato with 1/4 cup of the tapioca starch at a time.
• Season with the salt and rosemary; I also add half the bacon fat to the batter, which helps create a uniform texture.
• Process until smooth.
• Place the dough on the prepared baking sheet and use your hands to spread it into a rectangle about 1/4 inch sheet.
• At this point you can fill and roll, or cook as-is to create a flatbread.
• Brush with half the bacon fat and bake for 30 minutes.

• If a crispy texture is desired, broil for 2-3 minutes per side.
• Remove from the oven and brush with the remaining bacon fat.