Potato Leek Soup

I am trying to make soup on Friday night's for Shabbat for Blake. This is one I wanted to try so I looked up some recipes on foodgawker to try to copy. The recipe I used called for fennel, but I don't think I used it. The soup came out well, but it was not super flavorful or exciting. It would have been good topped with some cheddar cheese also.

Ingredients:
1 Tbs. butter
2 medium leeks, white & light green parts, sliced
2 cloves garlic, minced
1/4 C. white wine
3 largish, white-fleshed potatoes, peeled & diced
1 tsp. dried thyme
dash of cayenne
salt to taste
fresh chives, chopped (for garnish)
freshly ground black pepper (for garnish)

Directions:
Melt the butter in a large pot over medium heat. Add the leeks, and garlic, and cover. Reduce the heat to medium-low, and cook about 10 minutes, stirring occasionally. Increase the heat to medium-high, add wine and cook for 1-2 minutes. Add the potatoes, thyme, 5 cups of water, dash of cayenne, and season with salt. Stir, reduce heat to medium-low, cover and cook for 15-20 minutes, or until the potatoes are very soft.
Puree the soup using an immersion blender. Soup should be smooth. Taste and adjust seasoning as necessary. Ladle into bowls and garnish with chopped fresh chives and freshly ground black pepper.