Sweat the garlic, onion and celery until very soft and golden.
Add the rosemary, bay leaf, parmesan rind, beans, and a good grinding of black pepper.
Simmer gently until the rosemary and bay start giving off a delicious scent.
Add the stock and continue simmering gently for another 8-10 minutes.
Remove the bay, parmesan, and rosemary. Stir in the lemon juice (to taste). You can either puree all the beans to create a thick, creamy soup or puree only a cupful to make thick stock, keeping the remaining beans intact. Salt to taste.
Garnish with a hint of lemon zest and a drizzle of olive oil.