There are two approaches to this method. The first should be used if the base is going to be baked right away, and the second if the base is to be reserved to cook at a different time.
Method 1 is as Follows:
- Preheat a convection or static oven to 135°C/275°F.
- Place the ramekins (or other vessel in which the custard will be baked) in a sheet pan or hotel pan. The ramekins or the baking vessel should be shorter than the sheet pan or hotel pan, because you will have to pour water into the pan, and the ramekin or baking vessel needs to be surrounded by water to bake the custard properly.
- In a sauce pot, combine all of the milk (or the milk and heavy cream mix) with half the sugar and any flavorings (vanilla, cinnamon, and so forth).
- Combine the egg yolks and the other half of the sugar in a bowl. The bowl should be large enough to hold all of the components of the recipe.
- Bring the milk (or milk with heavy cream) to a boil. Turn off the heat, and slowly pour all of this liquid into the bowl with the egg yolks and sugar while whisking. This process is known as tempering the egg yolks, in which the eggs are brought up to a high temperature without coagulating the proteins in them, which would result in a lumpy base.
- Pass the mixture through a fine-mesh sieve. Pour into the prepared ramekins or vessel. A funnel gun works well for portion control. Fill nearly to the top.
- Place the sheet pan or hotel pan in the oven. Pour hot water into it, being careful not to get any into the custard base. The water should come up to the same level the custard is inside the ramekins or baking vessel. If it is too low, the “exposed” custard will overbake, since it will come into direct contact with the heat from the oven.
- Bake until you obtain a gelatinous jiggle. This means is that if you tap or gently move the ramekins or baking vessel, the custard will jiggle. This is because the protein in the eggs has coagulated just enough to have set but is still smooth and elastic. If it still sloshes around, it means the custard needs to bake further. If it is beyond a gelatinous jiggle and the surface does not look smooth, the custard is overbaked, and at this point there is no way to fix it.
- Once the custard has baked, take the sheet pan or hotel pan out of the oven (carefully so as to not spill any water into the ramekins), and take the ramekins or baking vessel out of the water. Place them on a clean sheet pan and let them cool at room temperature. Once they are cool, reserve refrigerated, covered well with plastic wrap. Discard after 2 days.