01 -
Melt butter over medium heat in a large pot. Add diced onion and sliced leek, cooking until soft and translucent, approximately 5 minutes.
02 -
Incorporate diced potatoes, stirring well. Cook for 3 additional minutes to allow the flavors to meld.
03 -
Pour in vegetable broth and bring to a boil. Lower the heat to a simmer, then add chopped cabbage and kale. Simmer for 15 to 20 minutes, or until potatoes are fork-tender.
04 -
Using an immersion blender, puree the mixture until smooth. For a heartier texture, retain some potato pieces as desired.
05 -
Stir in milk and season generously with salt, pepper, and nutmeg. Warm gently over low heat for about 5 minutes, ensuring the soup does not boil.
06 -
Ladle hot soup into bowls and top with sliced green onions before serving.