Cook the couscous: Add couscous to a heatproof bowl. Pour the boiling vegetable broth over it, cover with a plate, and let sit for 5 minutes. Uncover and fluff with a fork to separate the grains.
Cool it down: Spread the couscous on a plate or baking sheet so it cools quickly.
This keeps it fluffy and prevents it from steaming the veggies later.
Make the dressing: In a small jar or bowl, whisk together lemon zest, lemon juice, garlic, Dijon, olive oil, salt, pepper, and cumin if using. Taste and adjust salt or lemon as needed.
Prep the veggies: Chop the tomatoes, cucumber, red pepper, and onion. Rinse and drain the chickpeas.
Slice the olives. Chop the parsley and mint.
Combine: In a large bowl, add the cooled couscous, veggies, chickpeas, olives, herbs, and feta (if using).
Dress it: Pour the dressing over the salad and toss gently until everything is coated and evenly distributed.
Rest for flavor: Let the salad sit for 10–15 minutes so the couscous absorbs the dressing and the flavors meld.
Taste and finish: Adjust with a pinch of salt, a squeeze of lemon, or a drizzle of olive oil. Serve at room temperature or slightly chilled.