Set the Instant Pot to Sauté. Add the butter or olive oil, diced onion, and sliced kielbasa, then cook for 3 to 5 minutes, stirring occasionally, until the onion softens and the sausage develops light browned edges.

Add the minced garlic and optional smoked paprika. Stir and cook for about 30 seconds, just until the garlic smells fragrant.

Pour in the chicken broth and scrape the bottom of the pot thoroughly with a wooden spoon. Loosen every browned bit to prevent scorching and add that savory flavor to the cooking liquid.

Add the cabbage, kosher salt, and black pepper. Press the cabbage down gently if needed, but never fill the cooker above its maximum-fill line.

Lock the lid and cook on High Pressure for 3 minutes. If you prefer notably softer cabbage, set the pressure time for 4 minutes.

Allow a 5-minute natural release, then carefully quick-release the remaining pressure. Open the lid away from your face once the pin drops.

Stir in the apple cider vinegar, if using, and taste before adding more salt or pepper. Serve hot with some of the flavorful broth spooned over the kielbasa and cabbage.