In a large pot or Dutch oven, brown the Italian sausage over medium-high heat. Break it up with a spoon. Drain off excess fat.
Add the chopped onion to the pot and cook until softened, about 5 minutes. Stir in the minced garlic and red pepper flakes and cook for 1 minute more until fragrant.
Pour in the chicken broth and add the sliced potatoes. Bring to a boil, then reduce heat and simmer for 10-15 minutes, or until the potatoes are tender.
Stir in the heavy cream and chopped kale. Cook for another 5-7 minutes, or until the kale is wilted and tender.
Season with salt and black pepper to taste. Serve hot.
Notes
Enjoy this comforting soup as a main course or appetizer!