Bolognese with back

1/4 cup olive oil 1 small onion , finely choped 2 celery ribs , finely chopped 1 carrot , finely chopped 1 lb ground chuck salt fresh ground pepper 1 cup[...]

2 tablespoons extra-virgin olive oil 1/4 lb pancetta , cut into small dice (or ground) 1 lb ground sirloin 1 lb ground pork 1 onion , cut into small dice 3 -4[...]