Add the eggs and egg yolk to a bowl and whisk until smooth.
Add the egg mixture, sugar, milk, vanilla, salt, sugar and nutmeg to a different mixing bowl.
Whisk the mixture well and pour the mixture into ramekins. Cover the top of each ramekin with aluminum foil.
Pour water into the Instant Pot and place the trivet.
Put the ramekins on the trivet.
Close the lid and cook on high pressure for 8 minutes.
Once the cooking time is complete, wait for a natural pressure release.
Take off the lid the lid, and remove the ramekins (careful, they'll be hot!)
Add toppings, serve and enjoy :)
Video
Notes
It's really important to whisk the eggs and egg yolks well. It's meant to add a creaminess to the custard, but you don't want pieces of baked egg in it.
If you're worried that there are larger bits of egg, you can always pour the mixture through a small strainer to help remove them.
To keep the custard from sticking to the bowls, you can spray with nonstick spray or use coconut oil. It's not necessary, however, to do either.
Adding a little bit of cinnamon and sugar would be good. Pumpkin spice would be a great choice as well.
You can add toppings like whipped cream, caramel or hot fudge drizzle, or even fresh fruit.
For a savory egg custard, add garlic powder or shredded cheese, and remove the sugar, vanilla, and nutmeg.