Preheat oven to 400˚F and line a baking sheet with parchment paper.
Slice the cabbage head into 1" slices and arrange on the prepared baking sheet. Brush with half of the oil, garlic paste, fennel, salt, and pepper. Carefully flip and apply the remaining oil, garlic, and spices.
Roast for 20 minutes, and flip back over. Roast for another 20 minutes, or until crispy around the edges.
Serve warm, and garnished with coarsely chopped parsley.
As a note, these 'steaks' aren't quite as good warmed up, as they lose their crispiness, but leftovers are great sliced and added to casseroles.