In a bowl, combine the ground beef, breadcrumbs, garlic, salt, pepper, parsley and milk together in a large bowl.
Shape into meatballs.
After they have been formed, refrigerate them for 15 minutes to firm up before browning them in the frying pan.
Add enough oil to cover the bottom of a heavy frying pan. Allow the oil to heat up and then add the meatballs.
Brown the meatballs on all sides.
Remove from the pan and allow to drain on paper towels for a few minutes while you prepare the tomato sauce.
For the Tomato Sauce
Add the ingredients for the tomato sauce to the slow cooker.
Use the back of a spoon or the meat chopped to break up the whole tomatoes.
Add the meatballs.
Cook on low for 4 to 6 hours or until the meatballs are cooked through.
Serve over cooked spaghetti.
Notes
If you want a more smoother tomato sauce you can add the plum tomatoes to a blender to get the consistency you like before adding them to the slow cooker.