Place the chicken in a shallow dish and drizzle with the oil, lemon zest, lemon juice, garlic powder, salt and pepper, mixing with tongs to fully coat. Set aside.
Cut 4 pieces of foil. Place ¼ of the carrots, peppers, and green onions into the center. Top with the chicken breast and divide the olive oil mixture between each chicken breast. Place a piece of sliced lemon on top of each chicken breast.
Fold the foil to create a packet, pinching and rolling to seal.
Transfer to a large baking tray and bake for 20 minutes. Open the foil (careful, it’s hot!), and return to the oven for 10 minutes until the chicken is cooked through.
** You can make this on the grill by heating it to medium instead of the oven.