2. In a saucepan, combine lentils and water. Bring to a boil, then reduce heat and simmer for 20 minutes or until lentils are tender. Drain and let cool.
3. In a large mixing bowl, combine cooked lentils, cherry tomatoes, cucumber, and red onion.
4. In a small bowl, whisk together olive oil, lemon juice, salt, and black pepper.
5. Pour the dressing over the salad and toss to combine.