I added to the onions and leeks: one chopped carrot, a stalk of celery (also chopped), five diced potatoes and seven cups of vegetable broth and a teaspoon of salt, then brought the mixture to a boil and then let it simmer for 45 minutes. I think the simmering (patience) was the most important step. Just before serving, I added a teaspoon of ground black pepper and some fresh basil.
I served it with some crusty French bread and some Martinelli’s sparkling cider.
This is my contribution to Peace today: homemade potato leek soup. Delicious.