Stir together flour, baking powder and salt. Make a well in the center, then all water and oil. Gradually stir until dough forms. Knead dough gently 4 or 5 times. Roll out down. Brush with a little more olive oil, sprinkle with sea salt. Grill over medium heat until no longer sticking to grates. Remove from grill, top for pizza (or flip for plain flatbread), return to grill. Grill until cheese is melted and pizza is cooked through.