1. Preheat oven to 425F.

2. Spray a thin layer of oil onto a large sheet pan; set aside.

3. Place the potatoes in a bowl, add 1 Tbsp olive oil, oregano, salt, and pepper. Toss until they are coated in oil and seasoning. Spread them onto half of the sheet pan.

4. Place the tomatoes in the same bowl. Add 1 Tbsp olive oil, salt, and pepper. Toss until they are coated. Spread them out on the other half of the sheet pan.

5. Place pan in oven; roast for 20 minutes.

6. Butterfly each chicken breast so that they are of an even thickness, about 1/2" thick. Place the chicken in the oiled bowl used for the potatoes and tomatoes. Add 1 Tbsp olive oil, salt, and pepper. Toss until the chicken is coated. Set aside.

7. After roasting for 20 minutes, stir the potatoes and tomatoes, keeping them separate. Push each to the side gently, opening the centre of the pan for the chicken. Place the chicken on the pan, then return the pan to the oven and roast everything for another 20 minutes.

8. After 20 minutes, temp the chicken to ensure it's 165F. Change the setting on the oven from oven to grill.

9. Spread 2 tsp of pesto over the top of each piece of chicken. Place mozzarella slices on top of the pesto. Place the sheet pan under the grill.

10. Grill for 3-5 minutes, until the cheese is melted and slightly browned. Watch closely; it will cook very quickly under the grill.

11. Toss the lettuce with the dressing, then divide between two plates. Add one piece of pesto chicken to each plate, then top with some of the roasted tomatoes. Divide the roasted potatoes between the two plates; serve.