Mix together the mascarpone and herbs in a bowl and season well with salt and pepper.
Lift the skin away from each chicken breast and spread a quarter of the mascarpone mixture on each breast. Replace the skin and smooth carefully over the mascarpone mixture. Season to taste with salt and pepper.
Place the chicken in a baking dish and pour the wine around it. Dot the butter over the chicken.
Roast in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes until the chicken is golden and crisp. Remove from the oven and serve with garlic bread.