Place the chicken breasts between 2 layers of greaseproof paper and with a rolling pin bash them until they’re about 1cm thick. Season the chicken with salt, pepper and a little drizzle of olive oil. Rub this all over on both sides, then set aside.
Heat a good glug of olive oil in a medium-sized pan over a low heat. Prick 4 chillies, finely slice 4 garlic cloves and add to the pan along with the basil stalks and half of the leaves. Gently cook for 15–20 minutes, until softened but not coloured.
After 20 minutes remove the basil leaves (which should be beautifully translucent) and save them for later. Fish out the chillies, slice them open then scrape out and discard the seeds. Also scrape out the flesh and add it to the pan, discarding the skin.
Turn the heat up to medium and add the tinned tomatoes and remaining basil leaves, allowing the sauce to bubble away for at least 20 minutes, until it has thickened and the tomatoes have broken down. Tear up the olives and add to the pan along with the fresh tomatoes and most of the capers. Season to taste.
Place a griddle pan on a high heat and allow it to get super hot. Once hot, place the chicken breasts on the griddle and cook for a couple of minutes each side, or until golden and cooked through (juices should run clear when the meat is pricked). Leave to rest for a couple of minutes, then slice the chicken into long strips.
To serve, finely slice the remaining garlic and fry it in a little olive oil along with the remaining capers until crispy. Pour the tomato sauce onto a platter and lay the chicken slices on top. Sprinkle with your garlic, capers and the remaining chilli, deseeded and finely chopped. Scatter over some lemon zest, grated Parmesan, the rocket and the basil leaves.