egg or whatever the recipe calls for
Crack the egg into a small bowl. Beat it with a fork or small whisk until it is lightly beaten.
Measure 1 tablespoon of the heated liquid and pour it gradually into the egg, whisking or beating it constantly to incorporate the liquid into the egg.
Repeat this process, adding tablespoons of the hot liquid gradually until the temperature of the egg mixture is equivalent to the temperature of the hot liquid.
Pour the egg mixture slowly into the hot liquid, stirring to incorporate it.