Preparing the sauce:

1. Heat a splash of extra-virgin olive oil in a medium saucepan over medium heat. Add the onion and season with a good pinch of sea salt and freshly-ground black pepper. Cook, stirring occasionally, until softened, 5 to 7 minutes.
2. Add the garlic (and chilli flakes, if using) and cook, stirring constantly, for 1 minute, then add the passata, water, sugar and basil. Season with sea salt and freshly-ground black pepper, stir to combine and bring to a simmer.
3. Partially cover the saucepan with a lid (to avoid splattering), reduce the heat to low and simmer, stirring occasionally, for 45 to 50 minutes, or until thickened. Taste and adjust seasoning and fish the basil stems out. Set aside.

Preparing the chicken:

1. Slice each chicken breast in half horizontally then lightly pound to an even thickness of around ½ inch. If using chicken thigh fillets, do not halve them; simply pound them to the same thickness.
2. Prepare the dredging station: 1) Combine the flour, salt, garlic granules, Italian herbs and black pepper. You want to ensure that everything is well-incorporated. Transfer the seasoned flour to a wide, shallow bowl. 2) Whisk the eggs and black pepper in a separate wide, shallow bowl. 3) Combine the panko and parmigiano reggiano until well-incorporated then transfer to a large plate. 4) Combine the grated mozzarella and parmigiano reggiano in a bowl.
3. Bread the chicken: 1) Dredge 1 piece of chicken in the seasoned flour, turning to coat. Shake off any excess. 2) Dip it in the egg, turning to coat. Let the excess drip back into the bowl. 3) Finally, dredge the chicken in the panko-parm mixture, pressing firmly to help it adhere and ensuring that there aren’t any bare spots. Gently shake off any excess then transfer the chicken to a large plate or baking sheet. Repeat with the remaining chicken.
4. Place a wire rack in a large baking tray. This will help the bottom of the chicken stay crispy. Heat the vegetable oil in a large frying pan over medium/medium-high heat. You can check if the oil is hot enough by dipping in the of the chicken – it should sizzle immediately.
5. Working in 2 or 3 batches, cook the chicken, turning once, until deeply golden and crispy on both sides, around 2 minutes per side. Transfer the chicken to the wire rack.
6. Heat your oven grill on high. Generously spoon some of the sauce over each of the chicken piece, covering only about 80% of the surface to leave some crispy bits. Top with the cheese mix, again leaving some exposed parts.
7. Grill until the cheese is melted, bubbling and beginning to develop brown spots. Serve immediately, with the extra sauce, which you can reheat on low while the chicken is under the grill. Enjoy!