In a large pot or dutch oven, heat the olive oil over medium heat. Once hot, add the onion, carrot, celery and salt and cook until softened and onions have become translucent, about 5 minutes. Add the garlic, ground beef and Italian sausage and cook, stirring to break up the sausage and beef combine everything well. Once the meat has browned and cooked through all the way, add the pepper flakes, crushed tomatoes, tomato paste and red wine. Reduce and add beef broth. Stir well to combine and bring to a simmer. Cover and simmer for at least 20 minutes.