For the blini mix, tip the flour into a bowl, then season. Make a well in the middle, then add the egg yolk and half the milk. Whisk until smooth, gradually add the rest of the milk, then the butter and chives. Whisk the egg whites until starting to stiffen, then fold into the batter. To cook, lightly grease a frying pan, then sizzle spoonfuls for 2-3 mins on each side until golden, flipping them over when bubbling. Set aside and keep warm.