1.Whisk yeast, water and sugar in a small bowl until yeast dissolves. Cover; stand in a warm place about 10 minutes or until frothy.
2.Sift flours and salt into a large bowl; stir in yeast mixture, butter, milk and seeds. Knead dough on a floured surface about 5 minutes or until smooth and elastic. Transfer to an oiled large bowl. Cover; stand in a warm place about 1 hour or until dough has doubled in size.
3.Punch down dough; knead on a floured surface until smooth. Divide dough into 12 portions; shape each portion into a round roll. Place on an oiled oven tray, cover; stand in warm place about 15 minutes or until doubled in size.
4.Preheat oven to 200°C/400°F.
5.Using a sharp knife, slash the top of each roll. Brush rolls with egg yolk; sprinkle with extra seeds and salt, pressing down lightly.
6.Bake rolls about 25 minutes or until they sound hollow when tapped.
These rolls are best eaten on the day they are made. They can be frozen for up to three months.Note