Prep the Meat (and Bacon, if using!): In a large skillet over medium-high heat, brown the Italian sausage, breaking it up with a spoon as it cooks. If you're adding optional bacon, cook that first until crispy, then remove it with a slotted spoon to drain on paper towels, leaving some rendered fat in the pan. Once the sausage is cooked through, drain any excess fat from the skillet.

Sauté Aromatics: To the same skillet (with a little of that glorious bacon fat or a drizzle of olive oil if you didn’t use bacon), add the chopped onion. Sauté for 3-5 minutes until softened and fragrant, scraping up any browned bits from the bottom of the pan. Then, add the minced garlic and red pepper flakes (if using) and cook for another minute until just fragrant—be careful not to burn the garlic!

Combine in the Crockpot: Transfer the cooked sausage (and bacon fat, if you wish!), sautéed onion, and garlic mixture into your 6-quart or larger slow cooker.

Add the Liquids and Potatoes: Pour in the chicken broth and stir well. Add the thinly sliced or quartered potatoes. Give everything a good stir to combine and ensure the potatoes are submerged in the broth.

Slow Cook to Perfection: Cover your crockpot and cook on HIGH for 3-4 hours or on LOW for 6-8 hours, or until the potatoes are tender when pierced with a fork.

The Green & Creamy Finish: Once the potatoes are tender, stir in the chopped kale. Recover and cook for another 15-20 minutes, or until the kale has wilted and a beautiful vibrant green.

Enrich with Cream and Cheese: Finally, reduce the heat to low (or turn off if your crockpot runs hot). Stir in the half-and-half or light heavy cream and the grated Parmesan cheese. Continue to stir gently until everything is well combined and the soup is warmed through. Don't let it boil after adding the cream, as it can curdle.

Season and Serve: Taste the soup and season with salt and freshly ground black pepper as needed. Ladle generous portions into bowls, sprinkle with additional Parmesan cheese, and crumble the reserved crispy bacon (if using) over the top.