Make the sauce: Heat the olive oil in a large pot over medium heat. Add the onion and 2 teaspoons salt; cook, stirring, until soft, about 5 minutes. Stir in the tomato paste and cook, stirring, until the oil is red, 2 to 3 minutes. Add the pork and red pepper flakes and cook, stirring, until the meat is cooked through, about 10 minutes.
Add the crushed tomatoes and their juices and 1 cup water to the pot. Bring to a boil, then reduce the heat and simmer, stirring occasionally, until the sauce is reduced by one-third, about 1 hour.
Meanwhile, make the meatballs: Preheat the oven to 450 degrees F. Mix the ground pork, 1 tablespoon salt, the cherry peppers and their pickling liquid, the bread and eggs with your hands until combined. Roll into 24 golf ball-size meatballs.
Coat a rimmed baking sheet with the olive oil, then put the meatballs on it and bake until firm and cooked through, about 14 minutes; let cool 5 minutes on the baking sheet.
Divide the meatballs among bowls and top with the sauce. Serve with polenta, if desired.