Season the chicken breasts with salt and pepper, then turn them in plain flour.
Melt the butter with the oil in a frying pan over a medium heat and fry the chicken until golden on both sides and cooked through.Set the chicken aside on a plate, loosely covered with foil.
Creamy tomato sauce
In the same pan, fry the onion and garlic until the onion is soft and translucent.
Add the tomato purée and dried herbs, heat through for about a minute, then pour in the cherry tomatoes and the mascarpone/cream.You can also use chopped tomatoes if you prefer.
Stir well and let the sauce heat through for 10 minutes, then add the Parmesan and fresh basil.Crush some of the tomatoes if you like, but leave some whole.
Let the sauce simmer for another couple of minutes and season to taste with salt and pepper.
Return the chicken to the pan, scatter over a little finely sliced spring onion, basil or parsley, and serve with boiled rice, potatoes or pasta.