In a large pot, heat olive oil over medium heat.
Add the Italian sausage and cook until browned.
Remove the sausage and set aside, leaving drippings in the pot.
Add the diced onion to the pot and sauté until translucent.
Stir in the minced garlic and cook for 1 minute.
Pour in the chicken broth and bring to a boil.
Add the cubed potatoes and cook until tender.
Stir in the cooked sausage and chopped kale.
Reduce heat and add the heavy cream, stirring to combine.
Season with salt, pepper, and crushed red pepper flakes to taste.