Heat the oil in a pan with deep sides on medium heat. Fry the onion, minced and sliced garlic, and chilli pepper for 4–5 minutes until soft but not browned.
Add the tomatoes, seasoning with salt and pepper to taste. Simmer for another 5 minutes.
Stir the string beans into the sauce. Turn the heat to low, cover and simmer until the string beans are cooked, around 15–20 minutes. T