Preheat your oven to 325°F (160°C).
In a medium saucepan, heat the milk over medium heat until it begins to steam.
In a separate bowl, whisk together the sugar, eggs, and salt until well combined.
Slowly pour the hot milk into the egg mixture, whisking constantly.
Add the vanilla extract and mix well.
Strain the mixture through a fine sieve into a large measuring jug.
Pour the custard mixture into ramekins or a baking dish.
Place the ramekins in a baking pan and fill the pan with hot water halfway up the sides.
Bake in the preheated oven for about 30 minutes, or until set but still slightly wobbly.
Remove from the oven, let cool, and refrigerate for at least 2 hours before serving.