Put the tomatoes and onion in a large bowl with 1/2 tsp sea salt. Toss and leave to sit.

Cook the couscous in a pan of boiling salted water for 8-10 mins until tender (don’t overcook it – you want it a bit under so it can soak up the juices from the tomato), then drain really well. Cool for 10 mins then toss with the tomato and onion mixture.

Blend all the dressing ingredients with 1 tbsp water and 1/2 tsp sea salt until smooth. Drizzle some over the couscous, then serve the rest on the side for people to help themselves.