Add the chopped onion to the pot and cook until softened, about 3 minutes. Add the minced garlic and cook for 1 minute more until fragrant. Press Cancel.
Return the sausage to the pot. Add the chopped cabbage, chicken broth, diced tomatoes, thyme, salt, pepper, and rosemary. Stir gently to combine.
Secure the lid and set the vent to Sealing. Select Manual or Pressure Cook on High for 8 minutes.
When the cooking cycle finishes, allow the pressure to naturally release for 10 minutes, then carefully move the vent to Quick Release to remove any remaining pressure.
Open the lid. Stir the soup well before serving.
Notes
For a lower carb soup, omit potatoes if you add them.
You can add 1 cup of drained and rinsed cannellini beans during the last 5 minutes of pressure cooking for extra protein.