2 large leeks
6 large cloves of garlic
4 tablespoons unsalted butter
1/2 teaspoon fresh ground black pepper
1 cup white wine
4 cups vegetable broth
1 cup plain yogurt

Cut the leeks in half lengthwise and wash thoroughly, making sure to get rid of all the sand and grit. Cut into half moons. Smash or mince the garlic cloves. Melt the butter in a heavy stockpot over medium heat. Saute the leeks and garlic very slowly, never letting them brown or burn. Cook until the leeks are nearly translucent - about 10 minutes.

Add the white wine and pepper and let cook for about five minutes, then add the broth and turn the heat to a simmer. Simmer for 45-60 minutes.

Puree in a blender - hold the lid down with a folded towel or you will end up with splattered soup all over the kitchen! Puree in two batches, adding half a cup of yogurt into each. Eat slightly cool like this, or return to the pan and warm very gently over low heat - do not let boil.