Do the soaking thing with the beans - 1 hour after boiling or overnight, whichever you and your intestines prefer). Drain and rinse well.
Place beans in a saucepan with stock, onion, celery, carrots, and lemon juice. Bring to a boil, then simmer slowly, partially covered for 2 hours. Pureé veggies and beans with the liquid.
Reheat to a simmer or chill. Taste and adjust seasoning. Add a little more stock if it's too thick. Ladle into wide bowls and serve garnishes separately in smaller bowls.
Servings: 6