This recipe was adapted from the March-April 2007 Cook's Illustrated. I changed a few things because I either did not have all the ingredients or some of the preparation was too time consuming. The end result was a nicely flavored potato soup, that was not too garlicky.
2 Tbsp. unsalted butter
1 medium leek, white and light green parts halved lengthwise, washed and chopped small (about 1 cup)
3 medium garlic cloves, minced
1 whole garlic head, rinsed, and top third of head removed and discarded
5 cups low-sodium chicken broth
1 cup white wine
2 bay leaves
2 lbs. russet potatoes, peeled and cut in 1/2-inch cubes
1/2 cup heavy cream
1 1/2 tsp. minced fresh thyme leaves
Ground black pepper
Melt butter in a Dutch oven over medium heat. When foaming subsides, add leeks and cook until soft(do not brown), 5 to 8 minutes. Stir in minced garlic and cook until fragrant, about 30 seconds. Add garlic head, broth, wine, bay leaves and 3/4 tsp. salt. Partially cover pot and bring to simmer over medium heat. Reduce heat and simmer until garlic is tender, 30 to 40 minutes. Remove garlic, squeeze over a bowl until cloves slip out and mash with a fork. Return to pot. Add potatoes and continue to simmer, partially covered, until potatoes are tender, 15 to 20 minutes.
Discard bay leaves. Stir in cream and thyme. Using an immersion blender, process soup until creamy, with some chunks remaining. Season with salt and pepper. Serve topped with chopped parsley or chives.