For the sauce, in a large stock pot, heat the oil over medium heat. Add the onion and cook, stirring occasionally, until it begins to brown, about 12 minutes. Lower the heat to medium-low, and if the onion starts to burn, add a tablespoon of water.Add the garlic and cook, stirring constantly, until golden and fragrant, about 1 minute. The more color that develops on the onion and garlic, the more flavor they’ll addd to the finished sauce.Add the crushed tomatoes and the tomato paste and stir well. Add the sugar, oregano, salt, and pepper. Bring the mixture to a simmer, reduce the heat to low, cover, and cook stirring occasionally so that the bottom does not burn, for at least 30 minutes.Meanwhile, for the meatballs, break apart the beef in a large mixing bowl. Add the egg, bread crumbs, oregano, mint, salt, and pepper, and use your hands to mix. Do not overwork the beef, or the meatballs will be rough.Shape the meat mixture into about twelve 1-½ inch balls. Drop them into the sauce and stir gently to cover the meatballs in sauce. Cover the pan and cook, stirring occasionally to prevent burning, until the meatballs are cooked through, about 1 hour.Boil the pasta according to the package directions. Drain.To serve, divide the pasta among 4 plates or bowls. Or serve the meatballs on top of the pasta on a large platter. Sprinkle with Parmesan cheese; serve!