Place a parchment liner in the bottom of a 6 to 7 inch pan and spray with cooking spray (use a cake pan or springform).

Slice the mushrooms and dry them thoroughly.

Turn the Instant Pot on Saute. Add butter and the mushrooms. Cook until softened, about 5 minutes, stirring frequently. Add the mushrooms to the prepared pan, discarding the extra liquid from the mushrooms.

Add the eggs and heavy cream to a large bowl and whisk until light and frothy. Add the salt, thyme, and half of the cheese and mix well.

Pour the egg mixture into the pan over the mushrooms. Sprinkle with the remaining cheese. Cover the pan tightly with foil.

Add 1 1/2 cups of water to the Instant Pot stainless steel pot. Place a trivet inside and put the prepared pan on top of that.

Seal the lid, close the steam release valve, and press the “Pressure Cook” button until it’s on “High Pressure” and press “Pressure Level” button until it’s on “Normal” and press the +/- buttons until it’s on 00:25 for 25 minutes. When it’s done allow pressure to release naturally (do nothing and let the time start counting up to 00:10), then quick release the rest of the pressure. Carefully remove the pan from the Instant Pot using the trivet handles and allow to cool for a few minutes before serving.

Preheat oven to 375 degrees.

Spray a 9-inch pie plate with cooking spray to prevent sticking.

Slice the mushrooms and dry them thoroughly.

Add the butter to a medium nonstick skillet over medium heat and cook until softened, about 5 minutes, stirring frequently. Add the mushrooms to the prepared pie plate, discarding the extra liquid from the mushrooms.

Add the eggs and heavy cream to a large bowl and whisk until light and frothy. Add the salt, thyme, and half of the cheese and mix well.

Pour the egg mixture into the pan over the mushrooms. Sprinkle with the remaining cheese.

Bake for about 35-45 minutes or until the eggs are cooked and no longer liquid looking in the center.

Remove from the oven and allow to cool before serving.