Combine flour, yeast and salt in a large bowl. Mix in 310ml water. Add a bit more if too dry.
Tip dough out onto a floured surface. Knead until smooth. Transfer to an oiled bowl and cover. Allow to prove for 45 minutes or until doubled in size.
Divide dough into 10 equal pieces. Roll into a ball and make a hole in the middle. Stretch the hole out until it is about 6-8cm in diameter. Leave the bagels to prove for 30 minutes or until doubled in size.
Bring a large pan of water to the boil. Stir in the bicarbonate of soda.
Place the bagels in the boiling water, cook on each side for 30 seconds. Remove and place bagels on a baking tray lined with baking parchment.
Brush the tops with egg white. Sprinkle over the Whitworths Four Seed Mix and bake for 20-25 minutes or until golden brown.