Heat the oil in the saucepan over medium heat. Sweat the onions, potatoes and peppers for about 10 minutes while stirring vigorously, but do not let them brown.
Add the chillies and broth and bring to the boil. Then reduce the heat and simmer for 15 minutes. Puree half of the soup, add the ground peanuts and return to the pot with the rest of the soup.
Season with salt and pepper and garnish with chopped coriander, tomato pieces and peanuts.