In a large skillet, combine 2 tablespoons of unsalted butter and 1 tablespoon of olive oil over medium-high heat. Allow the butter to melt completely, creating a shimmering surface in the pan—this should take about 1-2 minutes.

Carefully add the cabbage wedges to the skillet. Sear each side for 3-4 minutes until they are golden brown and slightly caramelized. Once done, remove the wedges from the skillet and set them aside.

Lower the heat to medium and add the finely chopped yellow onion to the skillet. Stir and cook for about 5 minutes, or until the onions are soft and translucent.

Add 3 cloves of minced garlic and 1 tablespoon of Cajun seasoning into the skillet. Stir for about 1 minute to allow the garlic to become fragrant.

Pour in 1 cup of heavy cream, scraping the bottom of the skillet to lift any browned bits. Allow the mixture to simmer gently for about 2-3 minutes.

Stir in 1 cup of freshly grated Parmesan cheese until melted and smooth. Add 2 tablespoons of chopped fresh parsley.

Return the seared cabbage wedges back into the skillet, spooning the creamy sauce over them. Cover the skillet partially and cook for an additional 5 minutes on medium-low heat.

After the cooking time, remove the lid and check the doneness; it should be fork-tender yet firm. Serve warm, garnished with extra parsley if desired.