Heat the oil in a large pot, then add the beef and cook until browned all sides.
Add the onion and chilli paste. Fry for 2 minutes and then add the remaining ingredients.
Bring it to a boil, reduce to a simmer, cover and cook for around 90 minutes or until the beef is tender.
If there are whole pieces of tomato still in the pot, mash them with the back of a spoon.
Serve with couscous.