Heat the olive oil in a large stock pot over medium heat. Swirl to coat the bottom of the pan to coat. Add the onion and garlic and saute, stirring occasionally, until browned, about 7 minutes. Lower the heat if they begin to burn. The more color that develops on the onion and garlic, the more flavor they'll add to the finished sauce.
Once the onions and garlic are tender and caramel in color, add the crushed tomatoes and the tomato paste and stir until the mixture is smooth and well combined.
Add the remaining sauce ingredients (oregano through pepper), stir, and bring the mixture to a simmer. Reduce the heat to the lowest setting, cover the pot, and let cook for 30 minutes, stirring occasionally so that the bottom does not burn.
Make the meatballs: Break apart the beef as best you can in a large mixing bowl. Lightly beat the egg in a small bowl and pour evenly over the top of the beef. Add the bread crumbs, oregano, mint, salt, and pepper and use your hands to mix. You do not want to overwork you beef, or it will yield tough meatballs, but you do want to incorporate all of the ingredients into the ground beef so that each meatball will have a bit of the breadcrumbs and herbs and spices.
Shape the meat mixture into 12 balls, each about 1 ½ inches in diameter. Drop them into the sauce, stir gently so that they're all covered in sauce, and then let them cook, covered, for about 45 minutes to 1 hour over low heat, stirring occasionally to prevent burning. Serve over your favorite pasta.