In a large pot over medium-high heat, brown the ground beef and sausage until totally browned. Remove the meat from the pot with a slotted spoon and put it into a bowl. Set aside.
Discard any grease in the pot, but do not clean the pot. Drizzle in the olive oil. When it is heated, throw in the onions and bell peppers. Stir it around for 1 1/2 minutes, and then add the garlic. Stir and cook for an additional minute.
Pour in the wine and allow it to bubble up and reduce for about 1 1/2 minutes. Add the crushed tomatoes, marinara sauce and tomato paste. Stir to combine, and then add the sugar, salt, oregano, thyme, crushed red pepper if using and bay leaves. Stir, and then add the cooked ground beef and sausage and stir to combine. Place the lid on the pot and allow to simmer for 1 hour, stirring occasionally. Add a little water or some low-sodium broth if it needs more liquid.
After an hour, add the minced parsley and the Parmesan rind if using (or grated Parmesan if you prefer--or both!). Stir to combine, and then put the lid back on and allow it to simmer for another 30 minutes or so. Discard the bay leaves before serving.
Serve a big bowl of oiled noodles and the meat sauce so guests can serve themselves. Top each serving with minced parsley and grated Parmesan (or Parmesan shavings) and serve with a big piece of garlic-cheese bread.
This recipe can easily be halved! I just like to make a ton so I can freeze it.