Note: The mustard powder and hot sauce are so subtle in this soup but help enhance the other flavors, so although you may be hesitant to add them, I highly recommend it!
Remove the casings from the sausage if you purchased links. Cook and crumble the sausage and diced onions over medium-high heat until the onions are softened and the sausage is cooked through, 8-10 minutes. Drain grease. Add the garlic and cook for 1 minute.
Add the flour and cook for 1-2 minutes to remove the raw flour taste.
Add basil, oregano, cayenne, hot sauce, mustard powder, pepper, and red pepper flakes. Stir to combine.
Add the chicken broth and use a silicone spatula to “clean” the bottom of the pot. Slowly stir in the heavy cream. Bring to a boil, reduce to a simmer.
Add the kale and tortellini and simmer for 3-5 minutes. (If your tortellini needs longer cooking time, add the tortellini first, then the kale during the last 5 minutes.)
Taste the soup and add salt if desired. Start with ¼ tsp and add more after that if needed.
Transfer to serving bowls and serve! (This is great with Garlic Bread with Cheese!)