In a large bowl, combine your self-raising flour and greek yoghurt. Stir in a clockwise motion until a rough dough begins to form. Pour your dough onto a clean surface and knead for a couple of minutes. Cover with cling film and set aside while you prepare your other ingredients.
Prepare your spring onion, garlic and mozzarella and set it aside.
Grab your dough and slice it into 4 equal parts.
Flour your clean surface and then roll out a piece of dough until it's 0.75cm thick. Fold in the two outer edges to make a thin rectangular strip, and then roll out the dough again in one direction so it's around 0.75cm thick, to make a thin strip of dough. Cut off the top of the strip and the bottom of the strip to make a perfect rectangle.
Drizzle with oil on one side and then sprinkle the top half of the strip with scallions, garlic, and cheese. Slice the bottom half of the strip into mini strips to make a nice pattern. Roll up the bun and then repeat for all of the other buns.
Place each bun on some parchment paper and steam for 15-20 minutes or until fluffy.
Optionally, you can now pan-fry them for around 3 minutes on high heat to get a crispy bottom! Enjoy!