Spray the glasses with cooking spray or lightly coat them with a bit of oil.

If you are using slices of meat, break/cut them into smaller pieces and distribute them in the glasses.

Whisk eggs together with Parmesan, heavy cream, salt, and pepper.

Pour half of the egg mixture into one glass and the other half into the second glass.

It is important that the glasses are filled about 4/5 full - if there is too little in the glasses, they will float around in the water bath, and if there is too much, the egg custard will overflow.

Put the lids on and place the glasses in your water bath.

Cook them at 77 degrees Celsius (171 degrees Fahrenheit) for 1 hour and 10 minutes.

The egg custard is now ready to serve.