Created by Kerfuffle-Upon-Wincle (KUW) on October 16, 2014
Step 1: Heat 2 tablespoons olive oil in a medium skillet over high heat.
Step 2: Add 2 cups sliced onions and 1/4 teaspoon salt; cook, stirring frequently, until the onions begin to brown, about 5 minutes.
Step 3: Reduce the heat to low, add 2 tablespoons water and cook, stirring frequently, until the onions are golden brown and very soft, about 15 minutes.
Step 4: Cover and refrigerate for up to 3 days. Makes about 1/3 cup.
Step 5: Whisk whole-wheat flour, all-purpose flour, baking powder and salt in a medium bowl. Make a well in the center of the dry ingredients, pour in water and 2 tablespoons oil and whisk just until smooth. Stir in caramelized onions.
Step 6: Heat a large nonstick skillet over medium-high heat. Lightly brush the pan with some of the remaining 1 tablespoon oil. Using about 1/4 cup batter for each, pour the batter for 2 flatbreads into the pan and spread each into an approximately 5-inch circle using the back of a spoon.
Step 7: Sprinkle with a pinch of flaky salt (if using) and cook until the bread looks bubbly and mostly dry, 1 1/2 to 2 minutes. Flip and cook until golden on the second side, 1 to 2 minutes more.
Step 8: Remove from the skillet and wrap in foil to keep warm.
Step 9: Reduce the heat to medium, brush the pan with more oil and cook 2 more flatbreads, reducing the heat as necessary to prevent over browning. Repeat in 3 more batches with the remaining oil and batter.