Heat the oil in a large frying pan or wok, and add the onion and green beans. Cook over a medium heat for a few minutes until the onion is fairly soft.
Meanwhile, remove the leaves from the cauliflower, and grate the white part (or you can blitz it in a food processor if you prefer). Add the cauliflower rice to the pan, and allow to cook for around 5 minutes, stirring occasionally, until it's just starting to turn golden brown.
Add the spices, and season generously. Add the halved cherry tomatoes, and cook for a few more minutes, until the tomatoes are beginning to soften. Serve with plenty of fresh coriander (cilantro).