In a medium pot, combine lentils and water

Bring to a boil, then reduce heat and simmer until lentils are tender but not mushy

Drain excess water and allow lentils to cool

Transfer cooled lentils to a large bowl

Add cherry tomatoes, cucumber, red onion, olives, feta, parsley, and mint

In a small bowl, whisk together olive oil, lemon juice, Dijon mustard, garlic, black pepper, oregano, and remaining salt

Pour dressing over salad and toss gently to combine

Taste and adjust seasoning if needed

Refrigerate for at least 20 minutes before serving for best flavor