Sift flour into a bowl. Add sugar and salt and mix together.
Add two cups of whey and mix well using a whisk.
Add 1 egg and continue whisking. The mixture should be runny. If you insert a spoon the dough should coat the surface of the spoon.
Place a pan over medium heat and grease it with butter.
When the pan is hot use a ladle to pour the dough into the pan. 1/3 of a ladle should be enough to cover the surface of the pan. Hold a ladle with your left hand and the pan with the right one. When the dough touches the hot surface of the pan start moving your right hand in circular motions to make sure the dough spreads all over the pan. Place the pan back on the stove and wait for about a minute till the dough becomes golden brown on the bottom.
Flip the dough with a spatula and fry for another 30 sec.
Repeat with the rest of the dough.
Stuff each blin with cottage cheese. Either place 2 tbsp of cottage cheese in the middle of crepe and fold the edges like an envelope or spread cottage cheese on ¼ of the crepe, fold in half and again in half (you will get a triangle shape like on the picture).
Serve with sour cream, jam or honey.
Cast-iron pan works incredibly well for making blini. Although non-stick pan is fine too.