1. Cook the Sausage:
   Heat a large soup pot over medium-high heat. Add the sausage and chopped onion. Cook, breaking up the sausage with a spoon, until the meat is browned and cooked through, about 7-10 minutes.
   Stir in kosher salt and crushed red pepper. Add garlic and sauté for 1 minute, until fragrant.
2. Drain the Grease:
   Turn off the heat and carefully tilt the pot to ladle out any excess grease into a foil-lined container for disposal.
3. Thicken the Base:
   Turn the heat back to medium-high. Stir in the flour until fully incorporated. Slowly add the chicken broth, stirring constantly to avoid clumps.
   Gradually pour in the whole milk while stirring.
4. Add Potatoes:
   Scrub and slice the potatoes into ¼-inch thick coins. Add them to the pot and bring the soup to a low boil over medium heat. Reduce the heat to a simmer and cook for about 20 minutes, or until the potatoes are tender.
5. Prepare Kale:
   While the soup simmers, wash the kale and remove the thick stems. Tear or chop the kale into bite-sized pieces.
6. Finish the Soup:
   When the potatoes are tender, gently stir in the kale, heavy cream, and Parmesan cheese. Reduce heat to low and cook for another 15 minutes, or until the kale is wilted and tender.
7. Season and Serve:
   Taste the soup and adjust with salt and pepper as needed. Serve hot, garnished with additional Parmesan cheese and freshly ground black pepper.

Enjoy this rich, creamy, and comforting soup that tastes just like Olive Garden’s classic Zuppa Toscana!