optional: ½ tablespoon of granulated sweetener if you prefer a sweeter pizza sauce. (I use erythritol)
Preheat your oven to 220°C (or 425°F, gas mark 7 for non-fan ovens) and 180°C for fan-assisted ovens.
In a bowl, combine passata, tomato paste, onion powder, garlic powder, basil, and oregano. Set this mixture aside.
Season one side of the flattened chicken breasts with salt and black pepper.
Heat a frying pan over medium-high heat. Once hot, spray with cooking oil spray, add the flattened chicken breasts seasoned side down. (you may need to do this in batches if your pan is not large enough).
Season the tops of the chicken breasts with salt and black pepper, and spray them with cooking oil spray.
After 2-3 minutes, flip the chicken breasts over. They should be golden brown. Repeat the cooking process for the other side.
Transfer the cooked chicken breasts to an ovenproof dish.
Top the chicken with the pizza sauce and grated mozzarella cheese.
Bake until the cheese is melted, and the chicken is cooked through but still tender. This should take approximately 10-12 minutes.
If you prefer a more golden cheese topping, you can briefly place it under the grill for a couple of minutes.
Sprinkle the dish with fresh parsley for garnish.
Serve your delicious chicken dish with your choice of side dishes.