Preheat oven to 450 degrees F.
Cut cauliflower into 3/4 inch steaks. (See instructions in blog post)
In a large mixing bowl, toss cauliflower steaks with oil, marjoram, salt & pepper.
Spread cauliflower steaks onto rimmed baking sheet in a single layer.
Roast in oven approximately 15 to 20 minutes or until cauliflower is softened & brown on the bottoms.
Remove from oven and put cauliflower back into the large mixing bowl and gently mix with balsamic vinegar and parmesan cheese.
Place cauliflower back onto the baking sheet in a single layer and return to oven.
Roast for approximately 5 to 10 minutes or until cheese is melted.