In a large saucepan, cover white beans with cold water.
Add quartered celery and onion.
Place saucepan over medium heat and bring to a simmer.
Cook until beans are tender.
Remove from heat, season water with salt and allow to steep for 20 minutes.
In a saucepan over medium heat, add duck fat or olive oil.
Sweat small-diced carrot, celery and onion until soft.
Add white beans and lamb stock.
Cook until stock has reduced and coated beans.
Add halved tomatoes to warm thoroughly.
Remove from heat and stir in freshly chopped herbs.
Adjust seasoning and serve.