Heat olive oil in a large pot over medium heat. Add the Italian sausage and cook until browned, about 5-7 minutes.

Add the diced onion and sauté for 3-4 minutes until translucent. Stir in minced garlic and cook for another minute.

Incorporate diced potatoes and pour in the chicken broth. Bring to a boil, then reduce heat and simmer for 15 minutes until potatoes are tender.

Stir in the chopped kale and add red pepper flakes if desired. Simmer for another 5 minutes.

Reduce heat to low, and stir in heavy cream. Heat for 2-3 minutes, adjusting salt and pepper to taste.

Serve hot in bowls, optionally with crusty bread on the side.