Melt the butter in a large saucepan over a medium heat. Thinly slice the onion and garlic and grate the ginger. Add the onion to the pan and sweat for a few minutes until tender, then add the garlic, ginger and cumin seeds. Sweat for a minute or two more until tender and fragrant.
Step 2
Thinly slice the cabbage and add to the pan, stir well to combine with the seasonings and pan fry for 2-3 minutes.
Step 3
Add the stock and bring to a gentle boil. Reduce to a simmer and cook for 5-7 minutes more to soften the cabbage.
Step 4
Remove from the heat and transfer to a blender or use a hand held stick blender and process until smooth. Taste and adjust seasonings by adding a little salt and pepper if required.