Trim off roots and leaf ends of leek. Cut leek lengthwise in half; separate into leaves; rinse well under cold running water to remove all sand; drain well. Cut leek crosswise into 1/2-inch slices. Slice mushrooms. In 8" or 10" skillet over medium heat, in hot salad oil, cook leek and mushrooms until tender, stirring occasionally. In bowl, beat eggs, salt and 2 tbl water until blended. Reduce heat to low. Pour egg mixture over vegetables in skillet. Cover and cook 15 minutes or until mixture is set. To serve, cut intowedges.