Mix the yeast in the lukewarm milk and stand for 7-8 minutes and allow the yeast to activate.
Sift the flour into a bowl. Add the milk and yeast. Add the egg yolk, yoghurt, salt and whisk together by hand. Leave to stand for 2 hours covered with a cloth
Whisk the egg white until it forms white peaks. Fold the egg whites into the batter.
Leave to stand for half an hour.
Start heating the blini pan. Dip a paper towel in the sunflower oil and wipe around the pan. Continue to heat the pan to a medium heat. Add 1 tablespoon of mixture to the pan. Cook for 30 seconds. Turnover and cook for a further 15 seconds. Remove from the pan and put on a cooling rack.
Stack in a cloth/tea towel until ready to serve.
Serve with smoked salmon, maybe some cavier and creme fraiche and dill or chives