In a large pot or Dutch oven, cook the chopped bacon over medium heat until crispy. Remove with a slotted spoon and set aside, leaving the drippings in the pot.

Add the Italian sausage to the pot and cook, breaking it up with a spoon, until browned and cooked through. Remove with a slotted spoon and set aside with the bacon.

In the same pot, add the diced onion and cook in the remaining fat until softened, about 5 minutes. Add the minced garlic and red pepper flakes, cooking for one more minute until fragrant.

Pour in the chicken broth to deglaze the pot, scraping up any browned bits from the bottom.

Add the sliced potatoes to the pot. Bring the soup to a boil, then reduce the heat and simmer for 15-20 minutes, or until the potatoes are fork-tender.

Stir in the cooked sausage and bacon (reserving a little bacon for garnish if desired). Return to a simmer.

Stir in the chopped kale and heavy cream. Cook for another 5-7 minutes, until the kale is wilted and tender. Do not boil.

Season with salt and black pepper to taste. Serve immediately, garnished with grated Parmesan cheese if desired.