Roughly chop the cabbage into 1-inch pieces.
Dice your onion.
Set your Instant Pot to Saute mode.
Add the oil and pepperoni/sausage and saute until it starts to lightly brown.
Add your chopped cabbage, onion, and garlic to the Instant Pot. Sauté for about 5 minutes. Stir often with a wooden spoon.
Pour in the broth and the marinara sauce, then using the same wooden spoon scrape the brown bits from the bottom of the pot.
Set the lid on and secure the valve.
Turn the Instant Pot to High Pressure for 1 minute.
Once the timer is done, manually release the pressure.
Carefully open the lid and season your cabbage with sea salt and pepper if desired.
Sprinkle with freshly chopped parsley.
Serve hot.
Enjoy!