Step 1

Combine beans, stock and oil in a saucepan and bring to the boil. Reduce heat to medium and simmer until beans are softened and stock has reduced by two-thirds (15-20 minutes). Remove from heat, stir in sliced celery, and cool to room temperature (10-15 minutes).

Step 2

Toss bean mixture with herbs and celery leaves in a bowl, season to taste and serve drizzled with olive oil.