Rinse the quinoa thoroughly and soak it in water for 15 minutes.
Add quinoa and water to a pot and bring to a boil.
Once it starts boiling, reduce to medium-low heat and cook for 15 minutes.
Turn off the heat and let it steam for another 5 minutes.
Finely chop the cucumber, cherry tomatoes, bell pepper, and onion.
Mix the cooked quinoa and vegetables together in a bowl.
Make the dressing by combining olive oil, lemon juice, salt, and ground black pepper.
Pour the dressing over the salad and toss gently.