Put the flour in the mixing bowl. Add the yeast and salt on opposite sides and make a small well in the centre and add the olive oil.
Pour the kefir into a jug. In a 2nd jug prepare your water - just slightly warmer than you would normally use for making dough so that when it is added to the kefir it is still luke warm. Add 100ml of water to the kefir and stir well.
Add the combined liquid to the mixing bowl and mix for about 4 minutes.
Strip the leaves from the rosemary and chop finely. Remove the leaves from the thyme and chop finely chop. Add herbs into the mixing bowl and mix for a further 2 minutes on slow speed. If the dough is sticky then add a little more flour.
Cut and break up the feta on a small plate. Tip the flour on to the worksurface and flatten the dough into a large oblong. Put half the feta along the middle and fold over. Turn the dough around and flatten the dough a little more and add the remainder of the feta and fold the dough over again to enclose the cheese. Take each corner of the dough and fold into the middle and collect the dough into a ball.
Oil a bowl and tip the dough into it and cover with a cloth and keep in a warm place to rise. The dough should double in size which could take between one and 2 hours,
Line the loaf tin with baking parchment.
Tip the dough onto the work surface and roughly shape the dough into a cylinder and divide the dough into 7 equal sized pieces.
Gently shape each piece of dough into a ball. Place one ball in the centre and place the 6 balls around the side.
Cover the tin and again leave to rise. Meanwhile pre-heat the oven to 220ºC/200ºC fan oven.
After 30 minutes the dough balls should be touching each other.
Mix the herbs and olive oil for the topping and then with the aid of a pastry brush cover the tops of the rolls with the herbs and oil.
Bake for 25 minutes when the rolls should be a nice golden colour.