4 cups dry split peas
A Zen-like sense of patience
1) Put the split peas in a bowl and fill with water, swishing with your hand. Transfer to a colander and drain, with cold water running over. Repeat, rinsing the split peas 3 to 4 times. The water should run clear, and you should pick out all weird floating things and any gravel. The cleaner you can get the peas, the better the soup will taste.
2) Refill the bowl with water, and soak the peas for at least 2 hours. The peas will begin to look very green and swell slightly. Rinse them a final time at the end of soaking.
3) Transfer the peas to a medium soup pot and cover with at least an inch of water. You may have to add water as the peas cook, to get the consistency you want. Bring to a boil.
4. Skim the foam that rises to the top of the water. Be very diligent about this; the foam contains the little bits of dust and dirt that you weren't able to rinse off the dry split peas. The more foam you can get rid of, the better your final product.
5. Cook at a low boil for about 3 hours, adjusting heat and water level accordingly. The peas should be cooked until they disintegrate completely. Add salt towards the end of cooking, to taste.
This soup takes a long time to make, but is absolutely delicious and very, very simple. It keeps 2 to 3 days in the fridge, but serve it with a hot piece of baguette and it won't last that long.
Source of recipe: This is my recipe.