Rinse and soak the cashews in hot water for 3 hours or overnight.
Slice the leeks and make sure to thoroughly rinse them.
Heat up a heavy stock pot over medium low flame. Add a splash of water and the rinsed leeks with a pinch of sea salt. Saute a few minutes until wilted. Stir in the carrots and celery and cook a few more minutes.
Add the garlic, bay leaves and thyme and give everything a good stir. Add the wine and bring to a simmer. Cook a few minutes until reduced by half. ( this step is optional but it adds nice flavor)
Stir in the potatoes, cashews and veggie stock and bring to a simmer. Cover with a lid and cook until the carrots and potatoes are tender, about 20 to 25 minutes. Remove from heat and discard the bay leaves and thyme sprigs. (At this point reserve some of the veggies for garnish if desired).
Carefully transfer the soup to a powerful blender and puree until silky smooth. This is where it pays off to use a Vitamix, that machine is magical.
Taste the soup and adjust seasonings with more sea salt and black pepper at this point. Hit it with a squeeze of fresh lemon if desired.
OPTIONAL: Preheat a cast iron skillet over medium flame and pan sear the smoky tempeh until golden. Transfer to a cutting board and chop it up into small bits.
Ladle the potato chowder into bowl and top with some of the reserved veggies and crispy tempeh bits. Garnish with the chives and serve hot with saltine crackers or crusty bread.