Warm a large heavy-bottomed pot over medium-high heat and add a touch of oil. Cook the ground spicy Italian sausage, breaking it up as it browns. Drain excess fat and transfer sausage to a plate.
In the same pot with the residual grease, cook the diced bacon until crisp, then set it aside with the sausage. Leave 1 to 1 1/2 tablespoons of bacon fat in the pot.
Add the chopped onion to the pot and sauté for about 5 minutes until softened, stirring in minced garlic during the last minute.
Sprinkle the flour over the sautéed onion and garlic, stirring well to coat.
Gradually pour in the chicken stock while stirring, then add the diced potatoes and bring the mixture to a boil.
Let the soup simmer gently for about 15 minutes or until the potatoes become tender when poked with a fork.
Return the cooked sausage and most of the bacon to the pot; stir in the heavy cream and kale. Cook for another 5 to 10 minutes until the kale wilts.
Season with salt, pepper, and optional red pepper flakes to taste.
Serve the soup topped with the remaining crispy bacon and enjoy the comforting flavors!
