In a large skillet over medium heat, warm a splash of olive oil. Add your Italian sausage and cook for about 5–7 minutes, breaking it into smaller pieces as you sauté. Once done, transfer it to your crockpot.

In the same skillet, add diced onion and minced garlic, sautéing for about 3–4 minutes until the onion becomes translucent and fragrant. Pour them into the crockpot with the sausage.

Add diced potatoes and kale to your crockpot. Pour in enough chicken broth to cover the ingredients, stirring gently to combine everything.

Set your crockpot to low heat and allow the mixture to slow-cook for 6–8 hours or on high for 3–4 hours.

About 15 minutes before serving, stir in heavy cream along with salt, pepper, and red pepper flakes to taste.

Ladle your hearty soup into bowls, topping each with a sprinkle of freshly grated Parmesan if desired.