In a small bowl, place the breadcrumbs and red wine (or stock mixture), and mix to combine. Allow the breadcrumbs to sit in the wine (or stock mixture) while you prepare the tomato sauce.
Prepare the sauce.
In the liner of a 6-quart slow cooker, place all of the tomato sauce ingredients and whisk to combine well. Set the liner aside and return your attention to the meatballs.
Form the meatballs.
In a large bowl, place the ground pork and ground beef, and break up the meat gently with your fingers. Add the remaining meatball ingredients in the order listed, mixing gently to combine with your fingers. Do not overwork the meat or the meatballs will be tough.
Add the breadcrumb mixture, and again mix until just combined with your fingers.
Divide the meatball mixture into 12 to 14 pieces and roll each gently into a ball. Do not compress or pack the mixture.
Cook the meatballs.
Nestle each meatball into the tomato sauce in a single layer in the slow cooker liner. Cover and cook on high for 4 hours or on low for 8 hours or until the meatballs are cooked through. They should reach or exceed 165°F in the center on an instant-read thermometer.
The cooked meatballs can remain on your slow cooker’s “warm” setting for up to 1 1/2 hours. Turn the cooked meatballs over in the sauce to coat completely before serving.
Video
Notes
A note about wine Be sure to use a wine that you would like to drink with red meat, and make sure but that it doesn’t have an overly fruity taste. Cooking with wine, particularly in a slow cooker, tends to intensify its flavor, and you don’t want it to overpower the dish.For an alcohol-free version, use an equal amount of beef stock + 1 teaspoon red wine vinegar.In place of the grated cheese in the meatballs, use 1 ounce nutritional yeast flakes for a dairy-free version.