In a large bowl, combine the chopped kale, cooked quinoa, chickpeas, cherry tomatoes, cucumber, and red onion. If using, add the feta cheese.
In a small bowl, whisk together the olive oil, lemon juice, Dijon mustard, honey, salt, and pepper until well combined.
Pour the dressing over the salad mixture and toss gently to coat all ingredients evenly.
Let the salad sit for about 10 minutes to allow the flavors to meld and the kale to soften slightly.
Serve immediately or refrigerate for up to 2 days for flavors to develop further.