Preheat oven to 425°.
In a large bowl, coat broccoli in olive oil and toss with salt and pepper. Place on 1/3 of a well-oiled baking sheet. In the same bowl, toss Brussels with olive oil, salt, pepper, and honey. Place on 1/3 of the baking sheet. Continue by tossing chickpeas in olive oil, salt, pepper, and harissa seasoning. Set aside.
Drizzle more oil over chicken thighs and season generously with salt, pepper, honey, and harissa seasoning. Massage the spices into the chicken, including under the skin, until the meat is coated in spices. Place in the middle third of the sheet pan. Squeeze the juice of half a lemon over the chicken. Disperse chickpeas throughout the baking sheet and garnish with lemon wedges.
Bake for 45-50 minutes, tossing vegetables halfway through the cooking time. Cook until chicken reaches an internal temperature of 165° and vegetables begin to crisp and char.
Serve and garnish with charred lemon wedges.