For stuffing, combine ingredients in a bowl and season to taste with sea salt and freshly ground black pepper.
Using fingers, gently lift skin from spatchcocks to create a pocket. Spoon a quarter of the mascarpone mixture under skin of each spatchcock, then season birds. Preheat oven to 180C.
Heat olive oil in a large frying pan, add spatchcock skin-side down and sauté over medium heat for 5 minutes or until golden, then transfer to a roasting pan and roast for 15 minutes or until just cooked, add lemon juice to pan and swirl to combine. Serve immediately with strained pan juices, boiled potatoes and sautéed chicory, if desired.