Pour 1 cup of filtered water into the inner pot of the Instant Pot, then insert the trivet. In a large bowl, combine the eggs, cheese, spinach, butter, onion, black pepper, salt, mustard, paprika, cayenne pepper, cilantro, sage, and parsley. Mix thoroughly. Transfer this mixture into a well-greased, Instant Pot–friendly dish.
Using a sling if desired, place the dish onto the trivet, and cover loosely with aluminum foil. Close the lid, set the pressure release to Sealing, and select Manual/Pressure Cook . Set the Instant Pot to 40 minutes on high pressure and let cook.
Once cooked, let the pressure naturally disperse from the Instant Pot for about 10 minutes, then carefully switch the pressure release to Venting.
Open the Instant Pot and remove the dish. Let cool, serve, and enjoy!