How to Make It
To prepare crust, weigh or lightly spoon 75 ounces (about 1 1/2 cups) flour into dry measuring cups; level with a knife. Combine 75 ounces flour, 1 1/2 tablespoons sugar, and salt in a food processor; process until blended. Add 6 tablespoons butter, and pulse until the mixture resembles coarse meal. With processor on, slowly pour 5 tablespoons ice water through food chute; process until dough forms a ball. Shape dough into a 6-inch circle. Wrap in plastic wrap; chill 30 minutes.
Preheat oven to 400°.
Roll dough out to a 10-inch circle on a lightly floured surface. Place dough into a 9-inch round removable-bottom tart pan. Fold edges under; press dough against sides of pan. Line bottom of dough with a piece of foil; arrange pie weights or dried beans on foil. Bake at 400° for 10 minutes or until edge is lightly browned. Remove pie weights and foil; reduce oven temperature to 375°. Bake an additional 15 minutes or until crust is golden. Cool 10 minutes.
To prepare filling, combine 1/2 cup sugar and egg yolks in a large bowl; beat with a mixer at medium-high speed 3 minutes or until thick. Weigh or lightly spoon 1 ounces (about 1/4 cup) flour into a dry measuring cup; level with a knife. Add flour, satsuma orange rind, and the next 3 ingredients (through melted butter); stir just until combined. Pour mixture into cooled crust. Bake at 375° for 20 minutes or until filling is set. Remove from oven; cool completely. Reduce oven temperature to 325°.
To prepare meringue, beat egg whites with a mixer at high speed until soft peaks form using clean, dry beaters. Gradually add 1/2 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently fold in vanilla. Spread meringue evenly over filling, sealing to edge of crust. Bake at 325° for 25 minutes; cool 1 hour on a wire rack.