Pour 400 ml of boiling salted water over the couscous and let it soak for 5 minutes. Then fluff with a fork and let cool. Finely dice tomatoes and carrots. Chop the onion and garlic.
Mix everything, season with coriander, salt and pepper. Mix together oil, vinegar and ½ cup of hot water and mix in a bowl with the couscous and vegetables. Serve garnished with the mint.