Slice the cabbage in half to create 2 portions. Slice the core/stem out of both. Then slice each piece in half. You should have 4 smaller chunks of cabbage. From there, slice each into smaller strips.
Place the Instant Pot on the saute function and add the olive oil when the pot is hot.
Add the sliced sausage. Cook for 3-4 minutes until both sides are cooked through.
Add in the garlic and stir.
Add in the butter to the pan and allow it to melt. Deglaze the pan by scooping up the browned bits from the sausage along the bottom of the pan.
Add the sliced cabbage and broth. The cabbage will take up most of the room of the Instant Pot. It will wilt down when it cooks.
Close the pot and seal. Cook for 7 minutes on Manual > High-Pressure Cooking.
When the pot indicates it has finished, quick release the steam.
Open the pot. Season with salt and pepper. Taste repeatedly and adjust as necessary. Serve when cool.