In a large pot, sauté the leeks over medium heat, while stirring for about 4 minutes. Add a splash of water if they are sticking. Add the minced garlic, and continue to sauté while stirring for another minute.
Add the potatoes, nutritional yeast, white pepper, thyme, rosemary, bay leaves, salt, black pepper and enough veggie broth to just cover everything. Simmer, covered with the lid, until the potatoes are tender, about 10-15 minutes. Add the coconut milk, lemon juice, and lemon zest. Simmer for another 5 minutes uncovered.
Remove the bay leaves and discard them. Remove half of the potatoes and put them on the side in a bowl. Then, use an immersion blender to blend the soup until it's smooth. You can also use your blender for blending them. Add the potatoes that you removed back into the soup and stir to combine.
Ladle the soup into individual serving bowls, and garnish with green onions, black pepper, and maybe a sprinkle of thyme. Serve with some warm crusty whole grain bread!
I like to add a sprinkle of crushed hot pepper to mine!