To make the bean soup you have to start the day before. Actually whereas it is necessary to prepare stale bread you have to start few days earlier. Once, the bean soup in Sezze was also a way to use old bread hardened that otherwise would not have been eated. Today, however, very often you search for stale bread or you buy it well in advance and wait for it to harden. In Sezze there are also some old bread ovens that sell specifically for the soup.
The process is laborious but not complicated. Boil the beans kept in water for a whole night. The cooking must be done in abundant water and simmer (the beans must "mumble"). It is also practice put the pieces of pork rind or ham to flavor the beans (but it is optional).
Cook for about 50 minutes, add the onion and celery previously chopped, olive oil and tomato sauce. Cook for another 15 minutes, then add a rough pesto made chopping in a pestle the garlic, rosemary and fennel seeds (these are not optional! Fennel seeds give a unique flavor to the soup bean of Sezze).
Continue cooking for other 30 minutes, until the beans are thoroughly cooked.
Once cooked the beans you can proceed with the preparation of bread. You must remove the whole crust, then cut off the bread into thin slices and place them in layers in a salad bowl or baking dish. Then pour over the bread the soup (which must be very soupy) with a ladle by making sure that all the bread is dunk, the beans will remain on the last layer of bread.
Cover with a cloth and let it rest for a while '(to make sure that the bread soaks in the broth of the soup). Serve the portions with Gaeta olives and fresh onions or radishes. Finish with a drizzle of extra virgin olive oil (preferably made from local olives).

The bean soup is the most famous dish of Sezze, so famous that whoever tasted it remained entranced.
It is so famous and tasty that the poet Antonio setino Campoli dedicated to the bean soup of Sezze an entire poem, in his verses the poet narrates how this dish was pleasing to Pope Leo XIII (Vincenzo Gioacchino Raffaele Luigi Pecci) born in Carpineto Romano, another country of Lepine Mountains.
For some years now Sezze in August dedicates to this dish a festival, the Festival of Bread and Beans Soup by the cultural association Noi di Suso (www.noidisuso.it). This tradition began in 1995 and each year attracts tourists and gourmets from all over.
The bean soup is certainly cooked also in other countries of the area of Lepine Mountains, each with its own variant, but only the one of Sezze achieves the excellence. The key to the success of this dish is the use of bread of Sezze (also very popular) made by hand, also the process handed down from generation to generation is the secret of this recipe.
Each family has its own recipe and each one adds an ingredient that enhances and characterizes its soup. Typically you can add to the beans while cooking the pork rinds, the bone of the ham with a bit of meat still attached, or the pork shank, all this contributes to give more flavor to the broth.
Furthermore, it is the secondary choice of olive oil, must be the one made with local olives .. also cannot and should not be missing the fennel seeds even better if  wild fennel (or “mirride”). Often the pesto with garlic, rosemary and fennel seeds is prepared the day before so that everything is well flavored.
One last tip to best enjoy this dish is to put some fresh onion, radishes and Gaeta olives.

For each portion:
Energy: 503,88 Kcal
Energy from proteins: 12%
Energy from fats: 21%
Energy from carbohydrates: 67%
 
Dietary total fibre: 15,63 g
Alcohol: 0,00 g
Total proteins: 15,70 g
Animal proteins: 0,00 g
Vegetable proteins: 15,70 g
Total fats: 11,55 g
Animal fats: 0,00 g
Vegetable fats: 11,55 g
Cholesterol: 0,00 mg
Available carbohydrates: 89,80 g
Starch: 82,23 g
Soluble carbohydrates: 7,57 g