Combine milk and bread crumbs in a large bowl and set aside.
Dice onion and sweat on low heat until translucent and no color. Pull of heat and cool.
In same bowl with breadcrumbs and milk, add the remaining ingredients. Thoroughly mix and with a 2oz ice cream scooper, scoop meatballs on to a sheet tray. Once scooped, go back and roll meatballs into uniform balls.
Set a medium sauce pan over high heat and add a couple tablespoons of oil. Sear off meatballs on each side until golden and set in dutch oven. Do not crowed the pot. In a separate sauce pot heat up enough marinara to completely cover the meatballs. Once heated, pour over meatballs and cook in the oven at 300 degrees for an hour. Remove meatballs from sauce and save.
For the Pork:
Roughly dice the pork shoulder into 1-inch pieces.
In a medium sauté pan over high heat, add a couple table spoons of oil and sear off pork shoulder. Once seared, transfer to dutch oven. Heat up the meatball braising liquid and pour over the pork. Cover and cook in the oven for two hours at 300 degrees. Once done, remove the pork. This result of now two braised meats in the marinara is now, the gravy.
For the Sausage:
Roast the sausages on a sheet tray in a 400-degree oven for 15-20 minutes. Let cool and slice into half inch pieces.
For the Pizza:
Make two lines of gravy about an inch apart on the cheesed pizza. Top with cooked meatballs (cut in half), braised pork shoulder and sliced sausages and bake as directed. Top with grated parmesan and fresh basil.