In a large mixing bowl, whisk together the eggs, milk, cheese, salt and pepper. Make sure eggs are whisked well!
Add the vegetables to the egg mix and stir briefly.
Pour mix into a seven inch cake pan or any heat proof container that will fit inside your Instant pot.
Place the metal trivet inside the Instant Pot® and add 2 cups of water to the bottom of the pot. Place the Cake pan with eggs in it inside the Instant Pot® then close the lid. Make sure the steam valve is set to “seal” and then press “manual” and set the timer for 20 minutes. Once the times has gone off and your eggs are done cooking, do a manual pressure release by turning the steam valve to “vent”-be careful as hot steam will be coming out!
Serve casserole immediately while still hot.