Step 1 Preheat oven to 190°C. Butterfly chicken breasts (see tip). Combine breadcrumbs with two-thirds of the parmesan.
Step 2 Dip each chicken breast into egg and then into breadcrumb mixture. Place crumbed chicken in fridge to chill for 15 minutes.
Step 3 Spray a medium frying pan with cooking oil and set over medium–high heat. Cook onion and mushroom for 5 minutes, or until soft. Add passata, garlic, sugar and oregano; simmer for 5 to 6 minutes, then set aside.
Step 4 Transfer chicken to a non-stick frying pan set over medium–high heat. Pan-fry 2 chicken breasts at a time for 5 minutes per side, or until just browned.
Step 5 Pour half of the tomato sauce into a shallow ovenproof dish. Add pan-fried chicken and remaining sauce, then sprinkle with remaining parmesan and cheddar. Bake for 20 minutes.
Step 6 Scatter chicken with basil. Serve with Broccoli, lentil and mushroom salad.