In a large pan, heat 2 tablespoons of unsalted butter over medium heat. Add the sliced green cabbage and sauté for about 5 minutes until it wilts and becomes tender but still retains some crunch.

Stir in the chopped button mushrooms along with a pinch of salt and ground black pepper. Cook for an additional 5 minutes, stirring occasionally, then transfer the mixture to a medium-sized bowl.

In the same pan, combine 1 tablespoon of unsalted butter with heavy cream, sour cream, grated Parmesan cheese, and the finely chopped garlic. Stir over medium heat until the sauce thickens.

Gently return the cooked cabbage and mushroom mixture back into the pan. Stir until the cabbage is well-coated with the creamy sauce.

For an appealing finish, sprinkle extra Parmesan cheese and chopped parsley leaves on top before serving.