In a large skillet, brown the mini sausage balls until cooked through. This will take about 5-7 minutes. Drain off the grease and place the sausage balls on a plate lined with paper towels.
In a large pot, heat the olive oil over medium high heat. Add the onion and cook until tender, 3-4 minutes. Stir in the garlic and cook for 2 minutes. Stir in the red peppers, bay leaf, and red pepper flakes. Cook until peppers are soft, about 3 minutes.
Stir in the broth, tomatoes, and kale. Add the cheese tortellini and cook until tortellini is tender, 7-8 minutes. Stir in the fresh basil and season with salt and pepper, to taste. Stir in the mini sausage balls and heat until warm. Remove the bay leaf and serve.
You can make this soup vegetarian by using vegetable broth and omitting the sausage.