Combine flour, sugar and salt in saucepan. Blend scalded milk in slowly. Cook, stirring constantly, over medium heat until mixture thickens and boils. Continue cooking and stirring 1 minute.
Remove from heat and add a little hot mixture to beaten egg yolks. Quickly stir into mixture in saucepan. Return to medium heat and cook, stirring constantly, 3 minutes or until it thickens again and mounds slightly.
Slice peeled firm bananas into pie shell, making an even layer. Pour lukewarm filling over bananas. Spoon meringue over filling and spread over top, making sure it touches inner edges of crust all around pie.
Bake in moderate oven (350°) about 12 minutes, until peaks of meringue are golden brown.