Marcella Hazan's Braised Celery with Onion, Pancetta, and Tomatoes

Directions

1. Cut off the celery's leafy tops, saving the leaves for another use, and detach all the stalks from their base. Use a peeler to pare away most of the strings, and cut the stalks into pieces about 3 inches long (cutting on a diagonal looks nice). Alternately, if you plan on cooking long past tender (an hour or more), you can skip peeling the strings.
2. Put the oil and onion in a saute pan, and turn on the heat to medium. Cook and stir the onion until it wilts completely and becomes colored a light gold, then add the pancetta strips.
3. After a few minutes, when the pancetta's fat loses its flat, white uncooked color and becomes translucent, add the tomatoes with their juice, the celery, salt, and pepper, and toss thoroughly to coat well. Adjust heat to cook at a steady simmer, and put a cover on the pan. After 15 minutes check the celery, cooking it until it feels tender when prodded with a fork. The longer you cook them, the softer and sweeter they will become. If while the celery is cooking, the pan juices become insufficient, replenish with 2 to 3 tablespoons of water of juice from the canned tomatoes as needed. If on the contrary, when the celery is done, the pan juices are watery, uncover, raise the heat to high, and boil the juices away rapidly.