Lemon and Toasted-Coconut Meringue Pie

PreparationFor crust: Blend flour, coconut, and salt in processor. Add butter and cut in, using on/off turns, until mixture resembles coarse meal. Whisk egg yolk and 2 tablespoons ice water in small bowl to blend. Add to processor and blend until mixture begins to clump together, adding more ice water by teaspoonfuls if dough is dry. Gather dough into ball; flatten into disk. Wrap in plastic; chill 2 hours. (Can be made 2 days ahead. Keep chilled. Soften slightly at room temperature before rolling.) Roll out dough on floured surface to 13-inch round. Transfer to 10-inch-diameter glass pie dish. Fold overhang under; crimp decoratively. Pierce crust all over with fork; freeze 30 minutes. Preheat oven to 375°F. Line crust with foil; fill with dried beans or pie weights. Bake until crust is set, about 20 minutes. Remove foil and beans. Bake until crust is pale golden, about 15 minutes longer. Cool completely on rack. For filling: Preheat oven to 300°F. Whisk sugar and cornstarch in heavy medium saucepan to blend. Whisk in yolks, whole eggs, lemon juice, and salt. Whisk over medium heat until mixture thickens and just begins to boil around edges, about 6 minutes. Add butter; whisk until smooth. Cool 10 minutes. Pour warm filling into crust. For meringue: Using electric mixer, beat egg whites in large bowl until foamy. Add cream of tartar and 1 tablespoon powdered sugar and beat until soft peaks form. Beat in remaining sugar, 1 tablespoon at a time, then beat until stiff glossy peaks form, about 7 minutes. Gently fold 3/4 cup toasted coconut into meringue. Spread coconut meringue over warm filling, covering completely, sealing meringue to crust edges and mounding in center. Bake pie 30 minutes. Reduce oven temperature to 275°F; bake 30 minutes longer. Sprinkle remaining 1/4 cup toasted coconut over pie; continue to bake until meringue is light golden brown and set when pie is shaken slightly, about 15 minutes longer. Transfer pie to rack and cool completely, about 4 hours. (Can be made 1 day ahead. Refrigerate uncovered.)