Preheat the grill to 400 and lay a layer of tinfoil over part of the grate. In a large glass bowl, mix together all the meatball ingredients except the olive oil. Be careful not to make it a paste - don't overmix. But the two meats do need to be combined evenly. Once mixed, cover with tin foil and set aside at room temperature.
In a small cast iron pot, add all of the marinara ingredients except the onion and basil. Score the bottoms of the tomatoes before adding them. Put the pot on the grill (to the side of the foil) and the half onion directly on the grill grate as well. Good for 30 minutes, move the onion to the pot, and cook for an additional 30 minutes.
As the sauce smokes, add the olive oil to the meat and mix evenly. Form into large balls (should end up with about 10 meatballs), set on a pan, and chill in the fridge until ready to cook.
Once the sauce has cooked for about 45 minutes, add the meatballs onto the foil on the grill and cook for 20-30 minutes, until internal temp is 163-165.
After one hour of cooking, remove the pot from the grill grate. Pull the peels from the tomatoes. Take out the herbs and bay leaf, remove any tough parts of the onion and discard. Chop the onion roughly and add back to the pot. Using an immersion blender, blend it all together to desired consistency. Add the herbs back in, put on the stove and simmer until the meatballs are finished cooking.
When the meatballs are done, remove from the grill. Remove the herbs from the sauce, add the fresh basil, stir and ladle some over the meatballs. Put the remainder of the sauce in a bowl and serve on the side. Enjoy!