To prepare the mashed potato topping, place the chopped potatoes in a large saucepan and cover them with cold water. Bring the water to a boil and then simmer over medium heat for 10 to 15 minutes, or until the potatoes are tender. Drain the potatoes and return them to the pan. Add the chopped butter and milk, then mash until smooth.

While the potatoes are cooking, preheat your oven to 200°C (or 180°C for fan-forced).

In a large, deep frying pan, heat the olive oil and butter over medium-high heat. In batches, add the chicken pieces and cook for 2 to 3 minutes until they are browned. Once browned, transfer the chicken to a baking dish that is 6cm deep and has a capacity of 3.8 litres.

In the same pan, add the sliced leeks and chopped bacon. Cook, stirring occasionally, for about 8 minutes until the leeks have softened.

Next, add the thickly sliced mushrooms to the pan and cook for an additional 4 to 5 minutes until they are tender.

Pour in the dry white wine and bring the mixture to a boil. Allow it to boil for 2 minutes.

Sprinkle the plain flour into the pan and cook, stirring constantly, for 1 minute.

Gradually stir in the chicken stock and pure cream. Season the mixture with salt and pepper, then bring it to a boil before removing it from the heat.

Layer the baby spinach over the chicken in the baking dish. Carefully pour the cream mixture over the spinach and chicken, stirring gently to combine.

Spread the mashed potato evenly on top of the mixture in the baking dish.

Bake in the preheated oven for 25 to 30 minutes, or until the top is golden and the chicken is cooked through.

Once done, let the dish stand for 10 minutes before serving.