Sauce: Heat oil in a skillet, add onion and sauté for about 4 minutes, until transparent. Add garlic and sauté for another 1 minute. Add crushed tomatoes, basil, oregano, salt, pepper flakes, parsley and basil. Simmer the sauce for about 20 minutes until the sauce has thickened.
Meatballs: In a medium bowl, combine and mix together ground beef, ground pork, onion, garlic, egg, bread crumbs, parsley, salt and black pepper. Shape the meat balls and place on a baking sheet lightly greased with olive oil or lined with parchment paper or foil. Bake for about 20 minutes, or until the meat is no longer pink in the centre, turning them over halfway through. The outer surface on the meat balls should be a little crispy.Note: meatballs can be made ahead of time and placed in the refrigerator or cook them at the same time the sauce is simmering, and once cooked, then add them to the sauce.
While the sauce is simmering, and meatballs are cooking, bring a large pot of water to a boil, add ½ tsp of salt then add the pasta. Cook until al dente and drain. Keep about ¼ cup of the pasta water.
Check the flavour, adjust the seasoning at this time if needed. Spoon some of the sauce over the pasta, then add pasta to serving plates, add more sauce and meatballs. Garnish with sliced basil and Parmesan cheese.
Notes
Storing: refrigerate spaghetti and meatballs for 3-4 days. They both freeze well, so any leftover can be stored in the freeze in a sealed container or ziploc bag for 3 months and after that it will start to lose it's flavour.