Begin by making the curry paste. Place all of the ingredients into a food processor and process until well combined.
Place a large saucepan over a medium heat and add the olive oil and cook the curry paste for 5 minutes, until aromatic. Add the chopped onion, potatoes, mushrooms and carrots. Coat in the curry paste before adding the coconut milk. Reduce the heat to a medium low and simmer for 20 minutes, or until the potato is tender. Finally add the green beans and spinach leaves and cook for a few minutes so that the spinach wilts. Serve with steamed rice and pappadums.