Heat a large pot over medium-high heat. Add bacon and cook until browned and crisp along the edges, about 4-5 minutes. Remove the bacon and set aside on a paper towel lined plate. Drain excess grease, leaving about a tablespoon in the pot.
Crumble the sausage into large chunks and add to the pot. Cook until browned, another 3-4 minutes.
Add onion and garlic and cook until onions are slightly translucent, 1-2 minutes.
Pour in the chicken stock and scrape the bottom of the pan to release any browned bits.
Add the potatoes, increase the heat to high, and bring the soup to a boil.
Once the soup begins to boil, reduce the heat to medium-low, cover, and simmer for 5-8 minutes, or until the potatoes are fork-tender.
In a small bowl, whisk together the heavy whipping cream and cornstarch.
Stir the heavy cream and cornstarch mixture, kale, salt, and pepper into the soup. Simmer uncovered for 2-3 minutes or until kale is slightly wilted. Remove from heat.
Pour in apple cider vinegar and stir to combine. Top with bacon, parmesan cheese, and chili flakes. Serve immediately.