A straight forward whole-egg recipe that works.

Takes 30 mins.

Suitable for vegetarian diets.*

Makes 0.5 l.

Ingredients

2 cups	milk
2 tsp	vanilla essence
2	eggs
0.25 cups	sugar
1.5 Tbsp	cornstarch

Instructions

Heat milk and vanilla extract in a saucepan until it starts to simmer (don't let it boil), and remove from heat. Whisk eggs, sugar and cornstarch in a bowl until well mixed. Temper the egg mix with the hot milk: while stirring, add the hot milk to the egg mix a spoon at a time until about half of the milk has been added. Then pour the egg mix into the milk mix saucepan. For this part I found a food thermometer to be really useful, as custard thickens between 75 and 80°C. If it boils it will curdle, so don't let it get past 80°C. Place the saucepan on low heat, stirring constantly, until the custard begins to thicken, then remove from heat, and let it cool a bit. It will thicken more on cooling. Serve hot, chilled, or straight from the pot with a spoon like I know you will.

Adapted from https://www.allrecipes.com/recipe/258755/simple-custard/