1 large onion, finely chopped
1 medium potatoes, chopped
1 medium cauliflower, stalks and florets, roughly chopped
1 litre vegetable stock
salt and pepper
1 teaspoon cumin
1 teaspoon coriander
a pinch chilli powder
1 carton Greek yoghurt
Heat some olive oil in a pressure cooker or saucepan and fry the onion until soft. Add the cauliflower, potato and spices, mix well and fry for another 5 minutes or so. Season with salt and pepper and pour over the vegetable stock.
If using a pressure cooker, bring to pressure and cook for 15 minutes. If using a saucepan, bring to the boil and then simmer for 30-40 minutes until the potatoes and cauliflower are cooked.
Remove the lid and blend the soup with a stick blender. You can make the soup as smooth or as chunky as you like.
Pour in the milk and heat through. Stir in the Greek yoghurt and serve.