Preheat oven to 220C or 200C (fan).
Pound chicken to 1.5cm at the thickest part using a rolling pin or meat mallet. This is going to help make your chicken cook evenly and make it juicy.
Mix all the Spice mix ingredients in a small bowl.
Place the chicken breasts next to each other and upside down on a baking tray. Drizzle the chicken with about 1 tsp oil and spread over the breasts with your fingers. Sprinkle with about half of the Spice mix and rub it in.
Turn the chicken breasts over and, again, drizzle the other (top) side of the breasts with 1 tsp of oil and rub in the remainder of the Spice mix.
Position the breasts next to each other on the baking tray, without overlapping, as they won't cook evenly otherwise.
Bake for 18 minutes, or until the internal temperature is 165F/75C using a meat thermometer.
Remove from oven and wait for 3 to 5 minutes before serving - this also helps increase the juiciness factor.