To achieve a flat bread roll is easy. Use any bread recipe,(today i made a hybrid mix of No Fuss and Tang Zhong) and after the rolls were formed and risen, and as I placed them in the oven ,I placed an oven tray on top of them. I sprayed the underneath of the tray, that is the part that would sit on the rolls. with Canola spray. They continued to rise in the oven, but not up, but out. I again used the Muffin Top tray and brushed with egg wash.
The roll at the back of the photo is the 'control' roll, that is cooked without the tray on top.