Click onSAUTE on the Instant Pot, and when it reads Hot, add 2 tablespoons of butter and melt, add the onion and cook for 2 mins or until soft. Add garlic and cook for 1 min.
Next, add sliced kielbasa, and cook until browned. Add parsley, oregano, and Worcestershire. Stir.
Use some of the broth to deglaze the pot, if necessary.
Add the sliced cabbage, then the noodles and then, the broth. The water won't cover the noodles completely, but this is fine. Press them a bit into the broth. Don't stir.
Add 3 tablespoons of butter on top of the pasta.
Place the lid and lock it, make sure the vent is in a Sealing position, then click PRESSURE COOK for 2 minutes.
When the pot beeps, do a quick release. When pin drops, remove the lid, and hit CANCEL to turn the pot off.
Click on Saute, the noodles will not be fully cooked, but start stirring everything, and cook for 1 or 2 minutes until ready.
Hit CANCEL, stir in remaining butter, and add salt and pepper to taste.
Transfer Haluski to a serving bowl, and serve with sour cream, if desired, garnish with parsley.