Preheat and Prep (10 minutes):

Preheat your oven to 325°F (163°C).
Grease a 2-quart baking dish or individual ramekins with butter or non-stick spray.
Mix the Custard (5 minutes):

In a large mixing bowl, whisk together the sweetened condensed milk, eggs, hot water, salt, and vanilla extract.
Whisk until everything is well combined and smooth.
Pour and Bake (45-60 minutes):

Pour the custard mixture into the prepared baking dish or divide it evenly among ramekins.
Place the baking dish or ramekins in a larger baking pan.
Carefully pour hot water into the larger pan until it reaches about halfway up the sides of the custard dish.
Bake the custard in the preheated oven for 45-60 minutes, or until a knife inserted into the center comes out clean. The custard should be set but still slightly jiggly in the center.
Cool and Garnish (at least 2 hours):

Carefully remove the custard from the oven and take the baking dish or ramekins out of the water bath.
Let the custard cool to room temperature, then refrigerate for at least 2 hours before serving.
Before serving, sprinkle a light dusting of ground nutmeg over the top for an extra touch (optional).