Heat a large pot or Dutch oven over medium until hot. Add the ground beef or sausage to the pan, along with the chopped onion. Cook, breaking up the meat and stirring often, until meat is browned and onion is tender, about 10 minutes.

If there seems to be a big puddle of grease in the bottom of the pan, drain the excess fat and return the pan to the stove. This may not be necessary if using a leaner ground beef or sausage. Add the wine, if using, and stir to deglaze the pan. Allow the wine to reduce by about half before stirring in the remaining ingredients, except the spaghetti noodles and parmesan, and turn the heat down to low. Cover the pan and simmer sauce for 1 to 3 hours to thicken, stirring occasionally.

Once the sauce has thickened, cook the spaghetti noodles according to package directions. Drain pasta and serve with sauce, topped with freshly grated parmesan and parsley, if desired.

Slow Cooker Instructions: After browning the meat and onions in step one, transfer the meat mixture to the bowl of a large slow cooker. Stir the rest of the ingredients into the slow cooker with the meat, including the wine, if desired. Cook sauce for 6 hours on low or 3 hours on high before serving over cooked spaghetti noodles.