Step 1

Preheat oven to 400 degrees F. Toss cauliflower and peppers with 2 tablespoons oil and 1/4 teaspoon salt in a large bowl. Spread in a single layer on a large rimmed baking sheet; roast for 15 minutes.

Step 2

Meanwhile, combine 2 teaspoons harissa paste, brown sugar, garlic and the remaining 1 tablespoon oil and 1/2 teaspoon salt in a small bowl. Rub chicken all over with the harissa mixture. Stir the vegetables, then add the chicken to the pan. Roast until a thermometer inserted into the thickest part of the chicken registers 165 degrees F, about 20 minutes.

Step 3

Combine yogurt, the remaining 1/2 teaspoon harissa paste, lemon zest and juice, mint, parsley and pepper in a small bowl. Drizzle the sauce over the chicken and vegetables or serve on the side for dipping.