Heat a large pot over medium heat on the stove. Add the oil and onion and sautee until the onion becomes translucent. Add the garlic, red pepper and Italian seasoning and sautee 2 minutes longer.
Increase the heat to medium high, add the crushed and diced tomatoes, broth, salt and pepper. Allow to come to a slight boil and then reduce the heat to a simmer. Simmer for 15 minutes.
Add in the tortellini and allow to simmer approximately 7 minutes longer, or until the pasta is cooked through. Add in the heavy cream and basil and allow to simmer 3 minutes longer. Enjoy!