1. Peel and cut the potatoes into pieces.
2. Cut the cauliflower into small florets.
3. Slice the onion and chop the garlic.
4. Sauté the onion and garlic in a pot with the oil.
5. Add the curry paste, turmeric, and cumin, then mix.
6. Add the potatoes and cauliflower and coat with spices.
7. Pour in enough coconut milk to cover.
8. Let simmer for 25 to 30 minutes until the vegetables are tender.
9. Season with salt and pepper to taste.
10. Sprinkle with coriander before serving hot.