Melt butter in a pan. Add sliced leeks and celery. Saute until softened. Add 8 c. water, and malanga or 4 other types of potatoes. Bring to a boil and then simmer until tender.
In a separate pot heat water, and place 4 cut up potatoes in pot. cook until tender then set aside.
When Malanga is cooked and softened, place all ingredients in a blender and blend until smooth and creamy. Place back in stock pot and add cooked potatoes from other pot. Add soy milk, salt and pepper to taste and stir.
In a blender blend together cashews, warm water, brewers yeast, pimentos, lemon juice, smoked paprika, garlic and salt. Blend until smooth. Add to soup. and stir.
In a small bowl mix water with corn starch, stir well and add to soup. Bring soup to a boil stirring often and then reduce and simmer. Serve topped with non-dairy cheese and sprinkle smoked paprika on top.