Step 1: Cook the Sausage - Start by heating a large soup pot or Dutch oven over medium-high heat. Add the Italian sausage to the pot, breaking it up with a spoon or spatula as it cooks. Once browned and fully cooked through, remove it to a paper towel-lined plate while leaving behind 1-2 tablespoons of grease.

Step 2: Sauté Vegetables - Next, add the diced onion, carrots, and celery to the pot. Sauté these vegetables for about 4-6 minutes until they soften. Then mix in the minced garlic along with poultry seasoning, Italian seasoning, salt, black pepper, and red pepper flakes.

Step 3: Thicken the Broth - Toss in the flour to coat the vegetables evenly before adding cubed potatoes and chicken broth. Bring everything to a boil then reduce to a simmer for about 20 minutes until the broth thickens and potatoes are fork-tender.

Step 4: Final Touches - Stir in the drained white beans, Tuscan kale, heavy cream, and previously cooked sausage. Allow the kale to wilt down before finishing off with apple cider vinegar along with additional salt or black pepper if needed.

Step 5: Serve Hot - Finally, ladle your hearty soup into bowls and serve hot topped with fresh herbs like parsley or chives along with grated parmesan cheese. Enjoy this comforting dish with a slice of crusty bread on the side!