Preheat the oven at 200C.
Heat up the yoghurt in a sauce pan. If it's warm, take it of the heat.
If you use yeast, in a large bowl, add the yeast and agave syrup to the yoghurt and let is sit for 5 minutes. Do not stir it. After 5 minutes, stir it till the agave syrup and yeast are disolved.
If you don't use yeast, just simply mix the agave syrup and yoghurt together in a large bowl.
Mix the self-rising flour and yogurt until it comes together to form a ball.
Transfer the dough ball to a lightly floured work surface and knead the dough for about 5 to 10 minutes until it is smooth and elastic. Flatten and shape the dough into a roughly 20 cm disk.
If you use yeast, cover the bowl with a damp dish towel. Let rise in a warm place for 1 hour, until the dough has doubled in size. Punch the dough down, and let it rest for another 10 minutes.
Cut the dough into 4 equal pieces. Roll each piece of dough into a log roughly 20 cm long. Shape the log into a ring and transfer to a baking sheet.
Brush the tops of the bagels with egg wash (the beaten egg) and sprinkle it with sesame seasoning if prefered.
Bake for 20-25 minutes, until the bagels are golden brown.