How to Make It
In a large bowl, combine the flour with the salt. Add the water and lemon juice and stir until a sticky dough forms. Turn the dough out onto a lightly floured work surface and knead until smooth. Transfer the dough to a clean, oiled bowl. Cover with plastic wrap; refrigerate for 30 minutes.
Oil a large, rimmed baking sheet. Turn the dough out onto the sheet and divide it into 8 equal pieces. Press each piece into a 6-inch round that's 1/4 inch thick. Brush the rounds with 2 tablespoons of the melted butter and roll them up into cylinders. Cover the cylinders with plastic wrap and refrigerate for 15 minutes.
Unwrap the dough cylinders and flatten them into rounds again. Brush the rounds with 2 tablespoons of the melted butter; roll them up into cylinders. Wrap the cylinders in plastic wrap and refrigerate for 15 minutes. Repeat the flattening, brushing, rolling and chilling one last time.
Light a grill. Working with one cylinder at a time, unwrap and roll it out as thinly as possible between two sheets of waxed paper to form a round that's approximately 1/16 inch thick.
Carefully transfer 2 or 3 rounds at a time to the grill. Grill over high heat, turning once, until lightly charred and starting to puff, about 4 minutes. Transfer the flatbreads to foil and keep hot while you grill the rest. Serve hot.