Place the bacon in a deep stockpot and cook over medium-high heat until most of the fat has rendered, and bacon is crisp, about 2-3 minutes.
Stir in the onions, celery, and celery root or celeriac or sunchokes and sauté for 10 minutes, or until the vegetables are cooked, but still firm.
Add the water, clam juice or broth, thyme, bay leaf, and spices. Cover and simmer for 20 minutes.
Remove 2 cups of soup, and place in a blender. Drain and rinse the cashews, then add them to the blender. Blend for 30 seconds, until smooth.
Return the cream mixture to the pot and stir to incorporate.
Stir in the clams and simmer for another 5 minutes, until the clams are warm. Remove pot from heat and allow the soup to thicken for 10 minutes before serving.
When my friend, Dr. Tito makes this recipe he adds fresh corn, linguica and chopped carrots- all flavorful additions!
* Fresh clams take a bit more work, but if they are available to you, they amplify the flavor of this soup.