Rinse the lentils under cold running water until the water runs clear.

In a medium-sized saucepan, combine the rinsed lentils with 3 cups of water. Bring to a boil, then simmer uncovered for 20 to 25 minutes until tender.

Drain any excess water and transfer the lentils to a large bowl. Let them cool completely.

Bring a small pot of water to a boil, add the green beans and blanch for 2 to 3 minutes, then drain and rinse under cold water.

In a small mixing bowl, whisk together the olive oil, lemon juice, garlic, oregano, salt, and black pepper until smooth.

In a large bowl, mix the cooled lentils with the cherry tomatoes, cucumber, green beans, and red onion.

Pour the dressing over the salad and toss gently until well coated.

Fold in the crumbled feta and dill carefully to preserve their texture.

Chill the salad for 20 minutes if desired, then serve cold or at room temperature.