For both methods, slice end with stem off. Then on the very top of the head cut a 1x1x1" hole so steam and butter can soak in
Using pressure cooker first: Add 1 cup water to the pot. Remove stem from head of cabbage and set into steamer basket or on a trivet. Close lid and set to high pressure for 5 minutes, then do a quick release. * If you're not browning after, set to 7 minutes instead.
Preheat oven to 400 F. Lift steamer basket out and into a dutch oven with 1 c water or broth in bottom. Core out top just so butter will sit on top, sprinkle on seasonings and bake uncovered for 20-25 minutes or until lightly golden browned on top. Quarter, season with salt and pepper and enjoy.
Using only the oven: Remove stem from cabbage head + a bit more so butter will sit inside, pour 1 c water in pot, place trivet in middle so it can sit on it, place stem side up into dutch oven or pot with lid. Put butter in center core + sprinkle on all seasonings. Bake at 400 F for 1 hour covered.
Then flip head over and pour 2 tbsp melted butter over the top, bake uncovered for another 20-25 minutes until lightly golden brown on edges.