Prepare the couscous according to the instructions on the package. Replacesome of the water with the lemon juice.
Peel the onion and slice it into rings.
Wash the tomatoes and cut them in eights.
Wash the cucumber and cut half of it into slices.
If you wish, cut the lemon slices into small pieces, with the skin on.
For the tzatziki: peel, then grate the cucumber. Let it drain for 10 to 15minutes. Mix the yoghurt with the olive oil, lemon juice, garlic powder andchopped mint. Add the cucumber. Season with salt and pepper. Keep the tzatzikiin the fridge until you are ready to serve.
In a large bowl mix the couscous with the onions, tomatoes, cucumber, lemonpieces and olives. Season with salt and pepper and add a drizzle of olive oil.Serve chilled with the tzatziki.