In a large pot, heat 2 tablespoons of olive oil over medium heat. Once the oil is shimmering, add the crumbled turkey sausage. Cook for approximately 5-7 minutes, stirring frequently and breaking the sausage into smaller pieces until it is nicely browned and fully cooked.
After the sausage has cooked through, introduce the diced onion and minced garlic to the pot. Sauté the mixture for about 3-4 minutes, or until the onion softens and turns translucent, releasing its aromatic fragrance.
Pour in 4 cups of chicken broth and add the thinly sliced potatoes. Bring the soup to a boil, then reduce the heat to a simmer. Cover the pot and let it cook for 15-20 minutes, or until the potatoes are tender when pierced with a fork.
Stir in the chopped kale, heavy cream, and red pepper flakes. Allow the soup to simmer for an additional 5 minutes, enabling the flavors to meld beautifully.
Before serving, taste the soup and season it with salt and pepper to your liking. If you enjoy a spicier kick, don't hesitate to sprinkle in additional red pepper flakes.
Ladle the hearty soup into bowls, finishing with a sprinkle of freshly chopped parsley on top for a vibrant touch. Serve warm alongside crusty bread for dipping and savoring every bite.