Rinse the lentils under cold water and drain.
In a pot, add lentils and cover with 3 cups of water.
Bring to a boil, then reduce heat and simmer for 20-25 minutes until tender.
Drain any excess water from the lentils and let cool.
In a large bowl, combine diced bell pepper, cucumber, cherry tomatoes, red onion, and parsley.
In a separate bowl, whisk together olive oil, lemon juice, salt, and pepper.
Once lentils are cool, add them to the vegetable mixture.
Pour the dressing over the salad and toss to combine.
Taste and adjust seasoning as needed.
Refrigerate for at least 30 minutes before serving for flavors to meld.