Step 1: In a large skillet or Dutch oven, cook the diced bacon over medium heat until crispy. Remove the bacon with a slotted spoon, reserving at least 2 tablespoons of bacon fat in the skillet. Place the crispy bacon on a paper towel-lined plate to drain and cool, then crumble it.
Step 2: Add the thinly sliced cabbage to the skillet with the reserved bacon fat. Cook over medium-high heat, stirring occasionally, until the cabbage is tender and slightly caramelized, about 10-15 minutes. It should shrink significantly and become sweet. Season lightly with salt and black pepper as it cooks.
Step 3: Reduce the heat to medium-low. Add the minced garlic to the cabbage and cook for about 1 minute until fragrant. Be careful not to let it brown.
Step 4: Pour in the heavy cream and bring it to a gentle simmer. Let it cook for 3-5 minutes, stirring occasionally, allowing it to thicken slightly.
Step 5: Remove the skillet from the heat. Gradually stir in the freshly grated Parmesan cheese, a handful at a time, mixing until it’s fully melted and the sauce is smooth and creamy. If the sauce seems too thick, you can add a splash of reserved pasta water (if using pasta) or a little more cream. Taste and adjust seasoning as needed.
Step 6: Gently fold the cooked cabbage and creamy Alfredo sauce together. If adding cooked pasta, add it now and toss to coat. Stir in most of the crumbled crispy bacon, reserving some for garnish. Serve immediately, garnished with the remaining crispy bacon and a sprinkle of fresh parsley or more Parmesan cheese.