Leek and Potato Soup

This is the first recipe I've made from Alice Waters's new book The Art of Simple Food, and I was very pleased with it. I didn't have any thyme, so I had to skip that, and I think it would have been an improvement, but it was still a very nice soup. Went well with a sourdough baguette. Alice Waters's Leek and Potato Soup 50 min (incl. 30 min unattended) Trim roots and tough leaves from: 2 lbs leeks Cut leeks in half lengthwise and slice thin. Rinse in a bowl of cold water and lift out to drain. Melt over med heat in a soup pot: 3 tbsp butter Add the leeks and: 2 sprigs thyme 1 bay leaf salt Cook until soft, about 10 min. Add: 1 lb yellow potatoes [I used red], peeled [I didnt'], quartered or halved, and sliced Cook 4 minutes. Add: 6 c water/stock Bring to a boil, then turn down to a simmer. Cook until the vegetables are tender, but not falling apart, about 30 min. Remove bay leaf and thyme. Purée if desired, then add: 1/3 c crème fraîche or heavy cream [I used whole milk] Adjust seasoning as necessary and serve.