Combine the lukewarm water, dry yeast, and sugar in a large bowl.
Cover the bowl and leave to rest in a warm place for 10 minutes to allow the yeast to rise.
Add the milk, olive oil, finely chopped spring onions, chopped flat-leaf parsley, salt, turmeric, and type 550 wheat flour to the bowl with the risen yeast.
Mix well with a wooden spoon until the dough comes together. The dough is very sticky as it is high in liquid.
Line the Birkmann burger bun baking tray with baking paper. To do this, cut a baking sheet into quarters and trim the sides to make them nice and round.
Divide the dough into 4 even portions and slide into the baking tin, cover with a cloth, and leave to rest for 15 minutes.
Then brush the top with olive oil.
Place the baking tray in the oven for 40 to 45 minutes until the flatbread is baked through. Use a toothpick to test whether the flatbreads are cooked through.
Remove from the oven and leave to cool slightly.
Keep the flatbreads in an airtight container in the fridge for up to 3 days.