Step 1: Brown the Sausage and Onion
In a large soup pot or Dutch oven over medium-high heat, cook the Italian sausage and diced onion together for 8–10 minutes. Break up the sausage as it cooks. Once the sausage is fully browned and the onions are softened, drain any excess grease.

Step 2: Add Garlic and Flour
Stir in the minced garlic and cook for 1 minute until fragrant.
Sprinkle in the flour and stir to coat the sausage and onions. Cook for 1–2 minutes to eliminate the raw flour taste.

Step 3: Season the Soup
Add in the basil, oregano, cayenne (if using), hot sauce, mustard powder, black pepper, and red pepper flakes. Stir to combine everything thoroughly with the flour-coated mixture.

Step 4: Add Broth and Cream
Pour in the chicken broth, scraping up any browned bits from the bottom of the pot with a spatula.
Slowly stir in the heavy cream and bring the soup to a gentle boil, then reduce heat to a simmer.

Step 5: Add Kale and Tortellini
Stir in the chopped kale and tortellini. Simmer for 3–5 minutes, or until the tortellini is tender and the kale is wilted.
Note: If your tortellini requires a longer cook time, add it before the kale and cook accordingly.

Step 6: Adjust and Serve
Taste the soup and add salt as needed (start with ¼ teaspoon).
Ladle into bowls and finish with a sprinkle of red pepper flakes, if desired. Serve hot with garlic bread or crusty rolls.