Rinse lentils under cold water. Combine with 3 cups of water and a pinch of salt in a saucepan. Bring to a boil, then simmer for 15-20 minutes until tender. Drain and cool.

Chop mixed greens, slice cherry tomatoes in half, and dice cucumber. Soak red onion slices in cold water for 5 minutes. Set aside.

In a small bowl, whisk together lemon juice, balsamic vinegar, olive oil, honey or maple syrup, and Dijon mustard. Season with salt and pepper.

In a large mixing bowl, add lentils to the chopped veggies and mix gently. Crumble feta cheese on top and mix in fresh herbs if desired.

Pour dressing over the salad mixture. Toss gently to coat. Taste and adjust seasoning.

Serve immediately or chill in the refrigerator for up to an hour for enhanced flavor.