Heat a little olive oil in a heavy bottom pan.
Gently fry the onion over a low heat for 5 minutes until soft then add the garlic and ginger and continue to cook for a further minute.
Add the red curry paste and peanut butter and mix well.
Add the sweet potato and mix to coat in the paste. Add the coconut milk and water and bring to the boil then reduce heat and simmer for about 20 minutes until the sweet potato is cooked through.
Add the spinach and let it wilt down.
Serve on top of brown rice and garnish with a squeeze of lime and the peanuts.