Rinse the quinoa under running water.
Add water and quinoa to a pot and bring to a boil.
Once the quinoa is cooked, drain and let it cool.
Cut cucumber, tomato, onion, and other vegetables into bite-sized pieces.
Combine the cooked quinoa and vegetables in a bowl.
Make a dressing with olive oil, salt, and lemon juice.
Pour the dressing over the salad and mix well.
Transfer to a plate and serve.