Place the top oven rack in the center position and preheat your oven to 400°F. Line a large, rimmed baking sheet with parchment paper or a Silpat baking mat. This prevents sticking and makes cleanup easier.
Cut the stem off the cabbage head to create a flat, stable surface on the bottom. Carefully slice the cabbage from top to bottom into ½-inch thick sections. You should get about 6 nice “steaks” from one large head. Some outer leaves may fall off. Save those for another use or roast them alongside the steaks for crispy cabbage chips.
Transfer the sliced cabbage steaks to the prepared baking sheet, arranging them in a single layer without overcrowding. Lightly brush both sides of each cabbage steak with olive oil. Sprinkle with garlic powder and season generously with salt and black pepper to taste.
Place the baking sheet in the preheated oven and roast for 40-45 minutes, rotating the sheet once halfway through (around the 20-minute mark). The cabbage is done when it’s nicely browned and crispy on the edges with tender centers. Cook time will vary depending on the thickness of your slices and the moisture content of your cabbage. Check at 30 minutes and adjust as needed.
While the cabbage is roasting, make the dressing. In a medium bowl, combine the sour cream, sugar-free mayonnaise, Worcestershire sauce (if using), finely minced shallot, blue cheese crumbles, and heavy cream. Season with salt and black pepper to taste, and whisk vigorously until thoroughly combined and creamy. The dressing should be thick but pourable. Set aside until ready to serve.
Remove the baking sheet from the oven and let the cabbage steaks cool for several minutes. Transfer each cabbage steak to a serving plate or platter. Drizzle generously with the blue cheese dressing, then top with crumbled crispy bacon and additional blue cheese crumbles. Garnish with fresh chopped parsley and serve immediately while still warm. Enjoy!
