Heat a saucepan over medium heat and add a couple tablespoons of water.
Slice the white and light green parts of the leeks. The more green you add, the more off-white your soup will be so it’s up to you how much green to use. Add the leeks to the pan and sweat for about 5 minutes.
Peel and dice the potato and add it to the pan. Sweat for another couple of minutes then add 1 cup of the vegetable stock, reduce the heat to medium-low and partially cover the pan. Cook for 20 minutes, or until the vegetables are very soft and falling apart.
Cut the top off the head of garlic, drizzle over ⅛ teaspoon of oil and microwave “roast” it on high for 2 minutes or until soft. You can use a garlic roaster or place it on a plate and cover with a lid or plastic wrap.
Drain the cashews and blend them with ½ cup of fresh water until creamy. Add the contents of the saucepan, as much of the roasted garlic as you like (I like the whole head), lemon juice and salt to taste and blend until creamy. Add as much of the remaining ½ cup of vegetable stock as you want to reach the consistency that you like.
Serve the soup hot or chill it in the fridge for a couple of hours and serve cold. Garnish with pomegranate seeds and herbs, if desired.