Pat the chicken dry and set it on the prepared baking sheet along with the carrots. In a small bowl, whisk together the olive oil, harissa, lemon juice, cumin, oregano, salt and pepper. Pour the sauce over the contents on the sheet pan and toss until well combined, massaging the marinade into the chicken so that it is well coated. Spread the chicken and veggies into a single layer and transfer to the oven and roast until the chicken is cooked through and golden brown on the top and the carrots are fork tender, about 35 to 40 minutes, tossing halfway through the cook time.