Heat the oil in a dutch oven over medium-high heat.
When the oil is hot add the onion and cook, stirring occasionally, until softened, about 3 minutes.
Add the potatoes, curry powder, cumin, serrano, and 1 tsp salt to the pot. Stir well to coat the potatoes in the spices.
Pour in the vegetable stock and coconut milk. Bring to a boil then reduce heat to medium-low. Simmer until potatoes are tender, about 15 minutes.
Pour about ¼ of the potatoes and liquid into a blender and puree until smooth. Pour the pureed mixture back into the pot. Season with salt and pepper to taste.
Serve over rice and garnish with the cilantro and peanuts.
