Rinse the lentils thoroughly, then simmer them in water with salt for 20 to 25 minutes until tender but still firm. Drain and allow them to cool slightly so they maintain their texture in the salad.
Dice the cucumber, cherry tomatoes, bell pepper, and red onion into evenly sized pieces. Finely chop the parsley and mint to distribute fresh flavor evenly throughout the dish.
Whisk together olive oil, lemon juice, red wine vinegar, Dijon mustard, garlic, cumin, honey, salt, and pepper until the dressing becomes smooth and fully combined.
Combine the cooked lentils, vegetables, herbs, feta cheese, and walnuts in a large bowl. Pour the dressing over the salad and toss gently until every ingredient is lightly coated.
Let the salad rest for 10 to 15 minutes before serving so the lentils absorb the dressing and the flavors blend together more naturally.
Garnish with extra herbs, feta cheese, walnuts, and a squeeze of fresh lemon juice right before serving for the freshest flavor and presentation.