8 servings
Rinse and peel the leeks and potatoes.
Cut the white portion of the leek and the potatoes into rondelles, and soak them in water.
Sauté the leeks in a saucepan with butter, and add the potatoes, without letting them brown.
Add the pints of water, simmer with lid on, and add 1 tablespoon of salt when the water boils.
When the potatoes are well cooked, turn off the heat.
Blend the whole preparation, add more salt and pepper if necessary, then add the blueberries.
Add the cream at the moment of serving.