Peel, gut and dice the butternut. Peel and chop the onion, and fry it in a frying pan with some butter until properly browned. Add the water and the bouillon cube to a large pan and bring it to a boil. Add the wine, onion and butternut and let it boil gently for 20-30 minutes. Check the butternut to make sure it has softened. Now add salt, sugar, black pepper and the lemon juice. Mix the soup until smooth using a blender. This is a lot of soup, so blend it in batches.
In the meantime; heat up a frying pan and roast the almonds until they start to brown. Add 1/2 tablespoon of oil and some salt, and brown for another minute. Now transfer to a cutting board and let it cool off.
Pour the soup back into the pan and add corn starch. Bring it to a boil while stirring. Remove from the stove.
Chop the almonds with a knife and serve the soup in bowls with almonds sprinkled over.