Sautee the onion in oil (in the pot that will go in the oven), add sausages whole to brown a bit.
Once onion is cooked, remove sausages and add in tomato paste, cabbage, seasoning and mix.
Add sausages back on top with water (enough to just cover the cabbage but be able to evaporate in 40ish min).
Cover and bake in the oven on 350°F for 30-40 min.
Uncover once cabbage has cooked and bake to brown a bit.
Enjoy with bread on the side!