Place water and salt in a large mixing bowl. Whisking the water constantly, add the chick pea flour in a thin stream, paying careful attention not to form lumps, until all is blended. Whisk in olive oil and rosemary leaves and mix well. Allow to stand 2 hours. Spread bottom and sides of a 14inch by 10inch brownie pan with remaining oil and pour in batter. Place in oven and cook until edges are golden brown, about 30 to 35 minutes. Remove, cut into wedges and dust with black pepper. Serve warm or at room temperature.
