Hasselback the potatoes by thinly slicing the potatoes without fully slicing through. Alternatively you can simply quarter them. Add to a sheet pan.
Thinly slice the onion and place onto the sheet pan.
Slice the Brussel sprouts in half and place onto the sheet pan.
Drizzle everything on the sheet pan with avocado oil and season with salt and pepper. Bake in oven for about 20 minutes or until the potatoes have started to soften.
While those are cooking cut up the kielbasa and shredded the parmesan cheese.
Add kielbasa, parmesan cheese, and fresh thyme to the sheet pan and place back into the oven for another 15 minutes.
Once removed from the oven add on sauerkraut and enjoy!