In a large skillet, cook bacon until crisp about 5 minutes. Remove to a towel to absorb excess bacon fat. Add the onion to the same skillet used to fry the bacon and cook until it turns light brown in color, about 10 to 12 minutes. Add the tortellini to the pan cook until heated through. Add the cooked bacon, parsley and season with salt and pepper, to taste. Transfer to serving bowl and top with Parmesan cheese.
Preheat the oven to 375 degrees F.
In a large pot, heat the oil over medium heat and add the onion, garlic, and red pepper flakes. Saute for 2 minutes, then add the beef broth and 3 cups of water. Add all of the remaining ingredients, except the tortellini. Bring to a boil, then reduce the heat and let simmer for 5 minutes. Add the tortellini and simmer until the tortellini are cooked, another 5 minutes. Season with salt and pepper, to taste. Ladle into serving bowls and serve with Herb Focaccia, if desired.