Purple Potato Vichyssoise With Roasted Garlic

Ingredients

1 whole bulb garlic
1 tsp olive oil
1 tbsp butter
2 large thoroughly washed coarsely chopped leek, white and light green parts only
1 cooking onion, chopped
3/4 cup dry white wine
8 purple potato, peeled, diced
6 cups vegetable or chicken stock
1/2 tsp salt
1/2 tsp white pepper
4 fresh sprigs sage, or, 1 tablespoon dried sage
3 cups whole milk

Directions

1.Cut off the top quarter of the pointy end of the garlic bulb so that all of the cloves are exposed. Drizzle with olive oil, wrap in aluminum foil and bake in a 350°F oven for about 1 hour, or until the top is browned and the individual cloves are soft throughout. Let cool.
2.Melt the butter in a soup pot over medium-high heat. Add the leek and onion and stir for about 5 minutes, or until they are translucent but not yet brown. Add the wine and cook for 2 more minutes.
3.Add the potatoes and stock. Bring to a boil, then reduce heat to medium-low and simmer for 40 minutes. (Adjust heat as required to simmer.)
4.Add the salt, pepper, and sage. Let the soup cool.
5.Extract the individual cloves (squish them all out by applying pressure to the bottom of the bulb, or remove them individually with an escargot fork). Add them to the stockpot.
6.If using fresh sage, remove sprigs, then puree the soup in a blender or food processor. Refrigerate for a minimum of 1 hour.
7.Just before serving, add 1 part milk for every 3 parts soup, and blend in a blender for 15 seconds to aerate. Serve cold in chilled bowls.