breaking them up Let the meat cook, without stirring, until well browned on the bottom, about 3 minutes Add the butter and onions and scrape up the browned bits from the bottom with a wooden spoon Cook, stirring occasionally, until the onions are mostly softened and translucent, about 3 minutes Add the remaining garlic, the oregano, pepper flakes, and the remaining anchovy paste and cook, stirring and breaking up the meat, until fragrant, about 1 minute Add the tomatoes and bring to a boil, then reduce the heat to maintain a simmer Partially cover and cook until the sauce is thick and rich, about 1 hour Meanwhile, heat the vegetable oil in a 10-inch nonstick or cast-iron skillet over medium-high heat until it reaches 350°F (a meatball should sizzle vigorously when you dip the edge of it into the hot oil) Carefully transfer one-third of the remaining meatballs to the pan The temperature will drop to around 300°F—adjust the flame to maintain this temperature (the oil should continue to sizzle vigorously but not smoke) and cook until the meatballs are well browned on the first side, to minutes Carefully flip them with a small offset spatula or a fork and cook on the second side until well browned, about 3 to 4 minutes longer Using tongs, transfer the meatballs to a paper-towel-lined plate Repeat with the remaining two batches of meatballs, allowing the oil to return to 350°F before adding each batch Set the meatballs aside (Discard the oil or strain and save for another use.) After the sauce has cooked for 1 hour, add the meatballs and simmer for 10 minutes longer Season with salt to taste, stir in the basil, and serve, with grated ParmigianoReggiano (and pasta if desired) ...taste, stir in the basil, and serve, with grated ParmigianoReggiano (and pasta if desired)