Preheat oven to 400°F (200°C).
Mix together the flour, powdered milk, salt, yeast and baking soda.
Add the olive oil and warm water.
Mix together using your hand to bring the dough together. Knead for 10 minutes.
Cover the dough and put in a warm place and allow to double in size.
Pour out the risen dough onto a well floured surface. Cut into four pieces. With oil on your hands make a hole in the middle of each piece of dough and shape each into a ring.
Mix the egg white with the 2 tbsp of water and whisk together. Brush each bread round with the egg white wash.
Generously sprinkle the sesame seeds onto the rings of dough.
Bake for 30 minutes or until golden brown.