Put the dried beans in a large bowl and cover with cold water. Soak the beans overnight in the refrigerator.
Drain the soaked beans, place them in a large pot and cover with fresh cold water. Put the beans over medium-high heat and bring to a boil. Toss in the bay leaves and garlic. Reduce the heat to medium and simmer for 11/2 hours until tender. Drain the cooked beans and spread them out on a sheet pan to cool slightly.
Put about 1/2 cup of flour in a shallow platter and season it with salt and pepper; mix with a fork to distribute evenly. Toss the beans in the seasoned flour to coat completely.
Place a large skillet over medium-high heat and coat with the oil. When the oil is hot, add the pancetta, fry for a couple of minutes to crisp it up. Toss in the sage leaves and fry for about 1 minute. Remove the pancetta and sage to some paper towels; now you have a flavor base. Shake off excess flour from the beans and put them in the pan in a single layer. Fry the beans for a good 10 minutes to form a golden crust on the outside of the beans, tossing to cook both sides.
Return the pancetta and fried sage to the pan, stir everything together, and serve.