In a large mixing bowl beat the eggs for 1 minute, then add the Jiffy mix, melted butter, both cans of corn, and green chiles. Stir to combine.
Stir in the sour cream, and mix well
Pour the batter into a greased 7-inch round cake pan or push pan, and cover tightly with aluminum foil.
Pour 2 cups of water into the inner pot of an 8-quart or 6-quart Instant Pot, and place a trivet inside.
Place the cake pan on top of the trivet. Lock the lid and turn vent to Sealing position.
Pressure cook on high pressure for 45 minutes. Once the IP beeps that the cooking has been completed, allow a 5 minute natural release, then turn valve to quick release the remaining pressure.
Carefully open the lid, and using oven mittens remove the trivet by lifting the handles.
Place the cake pan on a wire rack, and discard the foil.
Top the casserole with shredded cheese, and broil in oven to melt it.
Garnish with chopped green onions and serve.