Preheat your oven to 425°F and line a large sheet pan (or two if needed) with parchment paper.
In a large bowl, whisk together olive oil, harissa paste, honey, cumin, smoked paprika, and salt until well combined.
Add the cauliflower florets, sweet potato cubes, chickpeas, bell pepper, and red onion to the bowl. Toss everything together until the vegetables are evenly coated with the harissa mixture.
Spread the vegetables in a single layer on the prepared sheet pan, making sure they're not too crowded—this helps them roast instead of steam.
Roast for 25-30 minutes, stirring once halfway through, until the sweet potatoes are tender and the cauliflower has crispy, golden edges.
Remove from the oven and immediately sprinkle with crumbled feta cheese and fresh parsley.
Serve hot with lemon wedges for squeezing over the top. Delicious over couscous, quinoa, or with warm pita bread on the side!