Preheat your oven to 375°F (190°C). Prepare the green cabbages by slicing off the tops and removing the cores, then rub with olive oil or butter, seasoning with salt and black pepper.

In a large skillet, heat olive oil over medium heat. Add onions, bell peppers, and garlic, sautéing for 5-7 minutes. Add smoked sausage and cook until browned, about 5 minutes. Stir in shrimp and Cajun seasoning, cooking until shrimp turns pink, about 2-3 minutes.

Stuff each cabbage with the shrimp and sausage mixture, packing tightly. Sprinkle cheese on top if using.

Cover the baking dish tightly with aluminum foil. Bake for 40-50 minutes until cabbages are tender. Remove foil and bake for an additional 10 minutes.

Let rest for a few minutes, then garnish with parsley and green onions. Serve hot.