Pod the beans, cover them with water, bring to the boil and skim. Turn the heat down to a simmer, then add the garlic, bay and chilli, and simmer until the beans are fully cooked, about 40 minutes. When they are cooked, set aside in their liquor.
Prepare the vegetables, cutting them into very fine dice. Make the gremolata, using the zest of the lemon, then juice the lemon.