Cook the lentils (if starting from dry): Rinse 1/2 cup dry green or brown lentils. Add to a pot with 2 cups water and a pinch of salt. Simmer 18–25 minutes until tender but not mushy.
Drain well and cool completely.
Make the dressing: In a small bowl, whisk the lemon zest, lemon juice, garlic, Dijon, and honey. Slowly whisk in the olive oil until the dressing looks glossy and emulsified. Season with salt, pepper, and red pepper flakes.
Prep the vegetables: Dice the cucumber, halve the tomatoes, finely chop the red onion, and roughly chop the herbs.
Keep the cuts bite-sized for a better mix.
Combine the base: In a large bowl, add the cooked lentils and chickpeas. Pour over half the dressing and toss to coat. This helps the legumes absorb flavor.
Add the fresh elements: Fold in the cucumber, tomatoes, red onion, parsley, and mint.
Add more dressing to taste and toss gently.
Finish and season: Add crumbled feta if using. Taste and adjust with more salt, pepper, or lemon juice. If it needs brightness, add a little extra zest or squeeze of lemon.
Rest (optional but better): Let the salad sit 10–15 minutes so the flavors meld.
Serve slightly chilled or at room temperature.