Brew a small cup of Vietnamese coffee.
Crack an egg and separate the yolk from the whites. Discard the whites.
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.
