In a medium heavy-bottomed saucepan over medium heat, fry bacon until crisp. Use a slotted spoon to remove bacon and drain on a paper-towel-lined plate. Pour off all but 1 tablespoon bacon grease. Add onion and cook over medium heat until softened and translucent, about 5 minutes. Add garlic and cook, stirring constantly, until fragrant, about 30-60 seconds.
Pour in chicken stock and add cubed potatoes. Bring to a boil and cook until potatoes are easily pierced with a fork, about 12 minutes.
Reduce heat and use a potholder to carefully til the saucepan to the side. Use a ladle to scoop out about 1-1 1/2 cups liquid; add to blender. Add cashews to a blender and blend on high speed until completely smooth, about 1 minute. Mash potatoes until desired consistency.
Pour blended cashew liquid into saucepan; add almond milk. Heat over low heat. Add salt and pepper; taste and add more as desired. At this point, you can also add a little more chicken stock to reach the desired consistency.
Ladle into serving bowls then top with bacon pieces, plenty of chopped chives, and freshly cracked pepper.
Be sure to serve this soup alongside a Whole30-compliant serving of protein to fit the meal template.Keep in an airtight container in the fridge up to 5 days.