For the quick pickled beetroot, combine all the ingredients for the pickled beetroot in a bowl and allow to sit in the fridge until you are ready to use it, at least 10 minutes.
For the blinis, pour the milk into a small saucepan and heat until lukewarm. Whisk in the yeast and leave to stand for 6-8 minutes until the mixture becomes foamy.
In a large mixing bowl, combine the flour and sugar with a generous pinch of salt and make a well in the centre.
In a large pyrex jug, mix together the buttermilk, melted butter and egg yolks. Whisk in the foamy yeast mixture and pour into the dry ingredients. Mix until you have a smooth batter and then cover and leave to stand in a warm place for 30 minutes.
Beat the egg whites in a clean and fat-free bowl until you have stiff peaks. Using a metal spoon fold this into the batter.
When you are ready to fry the blinis, heat a large non-stick frying pan over a medium high heat and brush the pan with a little melted butter. Add teaspoonful amounts to the pan and fry until golden on each side.
Allow to cool completely before topping with a generous dollop of crème fraîche, a slice of smoked salmon and some pickled beetroot.