Cà Phê Trứng

I stumbled across Cà Phê Trứng quite accidentally, and was quite intrigued by the concept of adding egg yolk to coffee. But I couldn't get the idea out of my mind either, so when I was making omelet for my hubby yesterday, I saved the egg yolk and made the coffee today.
Sweeter than I would like my coffee to be, it was surprisingly good. No "eggy" flavour, much less an "eggy" smell- if I have to describe it, I would say it tastes a lot like tiramisu might in a liquid form.
Definitely making it again- calories be damned!

1 egg yolk
2 teaspoons coffee powder
2 teaspoons of sweetened condensed milk
Boiling water

Method
Brew a small cup of filter coffee.
Put the yolk and the sweetened condensed milk in a small, deep bowl and whisk vigorously until you end up with a frothy, fluffy mixture. Add a tablespoon of the brewed coffee and whisk it in.
In a clear coffee cup, pour in your brewed coffee, then add the fluffy egg mixture on top.
Mix it well, and your cà phê trứng is ready.
In Vietnam, they serve the coffee over a bowl of hot water, so the coffee remains warm longer.