Turn the heat down to medium-low. If the chicken let out a bunch of fat, discard, leaving only about two teaspoons of oil. Add the onions and cook for about 3 minutes, next add the garlic and cook until fragrant. Add the harissa paste, broth, chickpeas and nestle the chicken atop. Brush the tops of the chicken thighs with harissa. Place in oven to cook, uncovered, for about 20 minutes. At the 20 minute mark, add the cauliflower all around (you may need to move the chicken around to fit all the cauliflower) and transfer back to the oven. Cook for an additional 15 minutes. Garnish with lemon wedges and Italian parsley.