Sandwich each chicken fillet between 2 large sheets of cling film, and pound with a meat hammer or the side of a rolling pin until thin and an even thickness and about 6 mm thick. Season well with salt and black pepper, dust with the flour, and set aside.

Heat 15 ml of the olive oil in a large frying pan over a low heat. Add the onion, and sweat for 5 minutes until soft. Add the garlic, and cook, stirring, for about 10 seconds.

Stir in the tomatoes and any juices, and bring to the boil. Reduce the heat to a low simmer, and cook for about 20 minutes. Stir occasionally, and keep crushing the tomatoes. Season well with salt and black pepper.

Meanwhile, heat the remaining oil in another frying pan, over a high heat. Add the chicken pieces, and cook for 5 - 8 minutes on each side until cooked through and golden. Remove from the pan, and serve immediately with the rich tomato sauce spooned over the top.

Cook's Notes:
A couple of teaspoons of pesto stirred into the sauce really pep up the flavours, or try stirring through a pinch of chilli flakes.