Combine rosemary, garlic powder, salt, pepper, and lemon juice, and olive oil in a bowl. Mix well.
Meanwhile, cook the vegetables according to your preference. You can steam the vegetables or stir-fry them using a little cooking oil. Sprinkle some salt and pepper and arrange in a plate. Set aside.
Rub the mixture over the chicken breasts. Arrange the chicken breasts in a resealable bag and pour-in the remaining mixture. Marinate for 15 to 30 minutes.
Preheat the oven to 375 degrees Fahrenheit.
Arrange the marinated chicken breasts in a baking pan.
Bake one side for 15 minutes. Turn the chicken breasts over and bake the other side for another 15 minutes or until internal temperature reads 160 degrees Fahrenheit (you will need to use a meat thermometer to get the internal temperature of meats).
Transfer the Baked Chicken on the plate where the vegetables are placed.
Serve your baked chicken with vegetables. Share and enjoy!