Prepare the leeks: Trim the roots and thick green tops off the leeks, leaving the pale part. Chop into thin slices and soak in a large bowl of cold water for about 5 minutes—this helps to remove dirt. Scoop the leeks out of the water, leaving the grit behind, and set aside.

Sauté the leeks: In a heavy-bottomed pot, heat a drizzle of olive oil over medium heat. Add the cleaned leeks and a pinch of salt, stirring occasionally for about 20 minutes until soft and fragrant, caramelizing slightly.

Cook the potatoes: Once the leeks are softened, add diced golden potatoes and bay leaves to the pot. Pour in 5 cups of water, making sure the potatoes are submerged. Increase heat to medium-high and bring to a gentle boil. Lower the heat, cover partially, and simmer for 15-20 minutes until potatoes are tender.

Simmer: Adjust seasoning with salt and pepper to taste. Continue to simmer, partially covered, for another 10 minutes to marry the flavors. The potatoes should be fork-tender.

Finish the soup: Remove from heat, stir in the fresh chopped dill, saving a little for garnish. Mix in half of the prepared cashew sour cream until combined.

Make cashew sour cream: Drain and rinse the soaked cashews. In a blender, combine cashews, lemon juice, and 1/3 cup of water. Blend until smooth.

Serve: Ladle the soup into bowls, garnishing each with a dollop of the remaining cashew sour cream and a sprinkle of fresh dill. Enjoy warm.