Add the cashews and water together in a bowl. Leave to soak (for a minimum of 30 minutes).
Begin by cleaning the pumpkin. Carefully slice the butternut pumpkin in half. Spoon out the inner seeds, and discard. Place the flat-side of each halve down, and slice pumpkin into thick pieces from top to bottom. Then thinly slice the skin off each slice, and dice the flesh into large bite-sized pieces. Aim for each piece to be relatively uniform in size, so they’ll cook at a similar rate.
Peel onion and garlic, and discard skin. Roughly chop each.
Add to a large saucepan or soup pot the diced pumpkin, onion, garlic and veggie stock. The liquid might not fully cover everything - this is totally okay!
Bring to boil uncovered, and then reduce to a simmer until the pumpkin is tender - roughly 35-40 minutes.
Once the soup has finished cooking, blend together the cashews and water using a stick blender or food processor until super smooth. Put aside.
Blend soup using a stick blender or food processor. If you’re using a food processor, do NOT put hot soup into the blender as this can be dangerous - let is cool first.
Once soup is blended, pour in cashew cream and mix until smooth. Taste-test and add salt and pepper to your liking.