Place all ingredients in large bowl, mix well, and shape into desired ball size.
Put the olive oil in a heavy bottomed pan and heat over medium heat. When the pan is heated, put in the meatballs, leaving a little space in-between each, and brown on all sides. Remove and set aside.
FOR THE MARINARA SAUCE:
Using the same pan, leave about 1 tablespoon of meatball drippings, and saute onion over medium low heat until soft.
Add the garlic and cook for another minute.
Add both cans of tomatoes, with their liquid, and bring to a boil. Reduce heat and simmer uncovered for about an hour, stirring occasionally.
Mix in the basil and add salt and pepper to taste. Add the meatballs to the sauce and heat through. Serve over pasta, sauteed cabbage, zucchini noodles, etc.
Notes
Can substitute ground turkey or chicken for the ground sirloin or pork
Can freeze leftover sauce and meatballs in a tightly covered freezer proof container for up to 3 months