Pre-heat oven to 200ºC ( 400ºF)
Add the flour, bread soda, and garlic powder to a bowl and stir well, then using your fingers rub in the butter until it starts to resemble fine breadcrumbs, then stir in the thyme leaves, onion, and spring onions.
In a jug whisk together the egg and yogurt, then make a well in the center of the flour mixture and pour in the egg and yogurt. Mix well until it forms a dough. If it is too sticky just add a little extra flour until it comes together like a dough.
Empty onto a floured worktop and knead gently, then cut out scones, or if you don’t have a cutter roll dough and cut with a knife.
Placed onto a floured tray and brush over a little extra egg. Bake for 15 minutes until golden.
Serve with a dollop of sour cream and a sprinkle of spring onion.