Blini (Russian Pancakes)

Step 1
Beat together milk and eggs in a large bowl until combined. Beat in sugar and salt. Mix in baking soda and citric acid until incorporated. Blend in flour, a little at a time, until combined. Beat in oil. Pour in boiling water, stirring constantly, until batter is thin and watery. Let rest for about 20 minutes.

Step 2
Melt 1 tablespoon butter in a small frying pan over medium-high heat. Pick the pan up off the heat. Pour in a ladleful of batter while you rotate your wrist, tilting the pan, so batter forms a circle and coats the bottom. The blini should be very thin.

Step 3
Return the pan to the heat. Cook blini for 90 seconds. Carefully lift up edge of blini to see if it's fully cooked: edges will be golden and bottom surface should have brown spots. Flip blini over and cook for 1 minute more.

Step 4
Transfer blini to a plate lined with a clean kitchen towel. Continue cooking remaining batter, adding 1 tablespoon butter to the pan for every 4 blinis. Stack blinis and cover with another kitchen towel to keep warm.

Step 5
Spread desired filling in the center of each blini. Fold 3 times to make a triangle shape or fold up all 4 sides, like a small burrito.