1.Combine the yeast, sugar and water in a small bowl. Leave to stand for 5-10 minutes or until the surface begins to froth.
2.Place the flour, cumin, sesame seeds and salt in a large bowl and make a well in the centre. Pour in the yeast mixture and mix to form a soft dough.
3.Turn dough out onto a lightly floured surface and knead for 8-10 minutes, or until the dough is smooth and elastic. Place in an oiled bowl and cover with plastic wrap. Leave for 3 hours in a warm place.
4.When dough has doubled in size, punch down and turn out onto a floured surface. Knead lightly for 1-2 minutes. Roll the dough out to a thickness of 5mm and cut into strips approximately 25cm long and 1cm wide. Roll lightly to form a thin snake of dough and place onto a baking tray lined with baking paper. Cover and allow to rise for 15 minutes.
5.Preheat oven to 180°C/160°C fan-forced. In a small bowl, beat the egg with ¼ cup of water. Brush the dough with the egg wash. Bake for about 15 minutes or until browned.
6.Remove the grissini from the oven, brush with olive oil and sprinkle with sea salt flakes. Return to the oven for a further 5 minutes or until golden brown. Cool on a wire rack. Store in an airtight container.
Suitable to freeze. Not suitable to microwave.Note