In a bowl, mix the capers, shallots, tomatoes, 100g of the butter and 1 tbsp parsley and season with salt and pepper.
Loosen the skin from neck end and push some butter mixture onto the breasts.
Heat oil in a roasting dish in the oven and then put the chicken skin side down so it rests on one of the legs (this is a great way to make sure the legs cook properly but the breast doesn’t dry out).
Season and roast in oven at 190C for 10 minutes on one side, 10 minutes on the other and then finish on its back for 30 minutes.
Take out and rest while you make the sauce.
Melt the rest of the butter in a pan and add the lemon juice.
Strain the cooking juices from the chicken and add to lemony butter.
Colour the sauce until golden.
Carve the chicken and place on a platter.
Add the remaining parsley to the sauce and pour over the meat.
Serve with small new potatoes in their skins and a green salad.