Step 1 Heat up the milk in a small pot until it is lukewarm. Transfer to a heat-resistant container, and rain the yeast over the warm milk. Stir to help the yeast dissolve, and let it sit for 5 minutes to activate.
Step 2 Meanwhile, transfer the egg yolks to a medium mixing bowl and slowly add the oil in a thin, steady stream while whisking vigorously. The idea is to emulsify the oil into the yolks.
Step 3Sift flours, 1 tablespoon of the sugar and salt into a separate bowl, and make a well in the center. Pour the yolk mixture and the dissolved yeast into the well, and start whisking from the center out, slowly drawing in more and more flour while working out the lumps. Once the mixture looks smooth, cover with a kitchen towel or plastic film and let rise at room temperature for 1 1/2 to 2 hours or until it has doubled in size.
Step 4In the stand up mixer, set up with the whisk attachment, beat the egg whites until foamy. Add the remaining 2 tablespoons of sugar and continue to whisk at high speed until soft peaks form. Fold the egg whites into the batter, alternating with the melted butter.
Step 5To make the blinis, heat up a non-stick skillet over medium heat. Coat the skillet with a thin film of equal parts oil and butter. Spoon dollops of about 1/8 cup of batter over the hot surface just as if you were making silver dollar pancakes. Flip each one when small bubbles start to form, and continue to cook on the other side for another minute. Put finished blinis on a separate plate. Wipe the skillet clean with a kitchen rag or paper towels and repeat previous steps to make more blinis.