Cook the Sausage: In a large pot or Dutch oven, heat the olive oil over medium heat. Add the Italian sausage and cook, breaking it apart with a spoon, until browned and cooked through. Remove the sausage from the pot and set it aside.

Sauté the Vegetables: In the same pot, add the diced onion and sauté until translucent. Add the minced garlic and cook for another minute until fragrant.

Simmer the Soup: Add the sliced potatoes to the pot, followed by the chicken or vegetable broth. Bring the mixture to a boil, then reduce the heat and simmer until the potatoes are tender, about 10-15 minutes.

Add Kale and Sausage: Return the cooked sausage to the pot and add the chopped kale. Continue to simmer until the kale is wilted and tender, about 5-10 minutes.

Finish with Cream: Reduce the heat to low and stir in the heavy cream or half-and-half. Warm the soup through, but do not boil. Season with salt, pepper, and red pepper flakes to taste.

Finish with Cream: Reduce the heat to low and stir in the heavy cream or half-and-half. Warm the soup through, but do not boil. Season with salt, pepper, and red pepper flakes to taste.