Peel and thinly slice the onion and garlic. Heat the olive oil in a large saucepan over a medium heat. Add half of the sliced onion and cook until golden and crisp. Keep turning and watching the heat as you want the onions to crisp but not burn. Remove from the pan and set to one side.
Step 2
Melt the butter in the same saucepan and add the remaining sliced onion and garlic. Sweat gently over a low/medium heat until tender and fragrant.
Step 3
Roughly slice the cabbage and add to the saucepan. Stir well to combine and pan fry with the onion and garlic for a few minutes to soften a little.
Step 4
4. Add the vegetable stock to the saucepan and bring to a gentle boil, then simmer for 5-6 minutes or until the cabbage is tender.
Step 5
Carefully transfer the soup to a blender, or use a hand held stick blender to process until smooth and creamy. Garnish the soup with the reserved crispy fried onions to serve.