Preheat the oven - Preheat your oven to 400°F (200°C).
Prepare the vegetables - Trim the ends off the Brussels sprouts and cut them in half. Peel and slice the red onion into thin wedges. Place the vegetables on a baking sheet lined with parchment paper.
Roast the vegetables - Drizzle the vegetables with olive oil and season with salt and pepper. Roast in the oven for 25-30 minutes, until the Brussels sprouts are tender and lightly browned.
Make the dressing - While the vegetables are roasting, make the dressing. In a small mixing bowl, whisk together the lemon juice, olive oil, Dijon mustard, honey, salt, and pepper.
Assemble the salad - In a large salad bowl, combine the roasted vegetables and chickpeas. Pour the dressing over the top and toss to coat. Add the feta cheese and chopped parsley and toss again.
Serve and enjoy! - Divide the salad between plates and enjoy immediately. This salad also keeps well in the fridge for a few days, so it's great for meal prep!