Heat a large pot over medium-high heat and add the sausage, breaking it into bite-sized pieces as it cooks. Brown for 5-6 minutes until the meat is no longer pink and has developed some color, which creates flavor depth. Remove the cooked sausage to a plate, leaving about 1 tablespoon of the rendered fat in the pot—this flavorful fat will enhance the aromatics. Don't clean the pot; those browned bits are liquid gold for building flavor.

Add the butter to the pot with the sausage drippings, then add the diced onion and cook over medium heat for 3-4 minutes until the onion becomes translucent and softens. Add the garlic and cook for just 1 minute, stirring constantly—garlic burns quickly and becomes bitter, so timing here is crucial. The combination of butter, rendered sausage fat, and aromatic vegetables creates the rich, savory foundation that makes this soup taste authentic.

Pour in the broth and water, then add the sliced potatoes, salt, pepper, and red pepper flakes. Bring to a boil over medium-high heat, then reduce to medium and simmer for 12-15 minutes until the potatoes are completely fork-tender and begin to soften the broth slightly. I slice the potatoes thin (1/4-inch rounds) so they cook evenly and help naturally thicken the soup as they break down slightly. Stir occasionally to ensure even cooking.

Add the kale to the hot broth and stir until it begins to wilt, about 2-3 minutes. Reduce the heat to medium-low, then slowly pour in the room-temperature cream while stirring gently—adding cold or room-temperature cream to boiling soup prevents it from breaking and curdling. Return the cooked sausage to the pot and stir to combine everything. Taste and adjust seasoning if needed; I often find the soup needs a touch more salt since potatoes absorb quite a bit.

Ladle the soup into bowls and top each serving with crispy crumbled bacon and a generous sprinkle of parmesan cheese. The warm soup will melt the cheese slightly, creating that creamy, indulgent texture that makes this soup so craveable.