In a medium bowl, stir together the flour, salt, yeast, and sesame seeds together. Using your fingers, work in the soft butter and water. Knead the dough on a lightly floured surface until it becomes smooth and pliable. Form the dough into a ball, place in a greased bowl, cover, and let rise for about an hour or more, until puffy. Turn the dough out onto a lightly floured surface and fold it over several times.
Divide the dough into 6 pieces. Roll each piece into a ball. Cover dough balls with a damp cotton cloth, and let sit for 10 minutes.
Using a floured rolling pin, roll each ball of dough into an 8 to 9-inch circle about 1/8-inch thick.
Heat a heavy frying pan or griddle over medium heat. Spray the pan with non-stick spray. Place dough round in the pan, and cook the first side until the flatbread starts to bubble and has some golden brown areas, about 1-2 minutes. Flip, and continue cooking until the second side is also golden, about 2 more minutes. Stack breads as they come off the griddle to keep them warm and soft.