In a saucepan, heat the oil and fry the diced onion.
Then add the can of tomatoes and the can of coconut milk and add an almost full can of water. Slowly bring the whole to a boil, add the grained broth, and season to taste with salt and chili.
Puree finely with a hand blender. Bring the soup to the boil once, add plenty of chives and arrange in plates.