Instructions
1
For the topping, boil the potatoes in salted water until tender. Drain and push through a potato ricer, or mash thoroughly. Stir in the butter, cream and egg yolks. Season and set aside.
2
For the filling, melt the butter in a large pan. Add the shallots, carrots and celery and gently fry until soft, then add the garlic. Pour in the wine and cook for 1 minute. Stir in the tomato purée, chopped tomatoes and stock and cook for 10–15 minutes, until thickened. Add the shredded chicken, olives and parsley. Season to taste with salt and pepper.
3
Preheat the oven to 180C/160C Fan/Gas 4.
4
Put the filling in a 20x30cm/8x12in ovenproof dish and top with the mashed potato. Grate over the Gruyère. Bake for 30–35 minutes, until piping hot and the potato is golden-brown.