Slice sausage into 1" thick dials and cut cabbage into quarters or 8 equal pieces (more, smaller pieces will yield more tender cabbage)
Put wedges into 9x13" aluminum pan with sausage surrounding them. (if adding onions sprinkle those in now too)
In a bowl whisk together olive oil and seasonings. Pour on top of cabbage and cover pan with foil.
Cook for 20 minutes, then lift foil and rotate cabbage to other flat side, cook for another 20 minutes, then remove foil and cook for 40 more minutes uncovered. (note: this timing is for quartered cabbage, if you cut it smaller it may take less time)
Check and see if it's as tender inside and browned on outside as you'd like it to be, remove and enjoy immediately for best taste and texture.