First, boil the sweet potato for 15 minutes with a pinch of salt.
Then, leave to cool.
Next, spread butter on a slice of bread.
Secondly, cut the goat cheese and green onions into small pieces.
Break the walnut core into small pieces, too.
Thirdly, cut the sweet potato into 5 mm slices.
Add it to the slice of buttered bread.
Add some cheese, green onion, and walnuts over the sweet potato.
Finally, put a slice of bread on top.