Cosy Chicken Pie with Potato & Celeriac Mash

1. Preheat your oven to 200°C/Fan 180°C/Gas 6. Peel the potatoes and chop them into bite-sized pieces. Slice the roots off the celeriac on an angle, leaving as much flesh behind as possible. Give the celeriac a rinse, then peel off the rest of the skin and chop to match the potato. Pop the potatoes and celeriac into a pan and cover with cold water. Pop the pan on a high heat, cover with a lid and bring to the boil. Reduce the heat and simmer for 15-20 mins till the potatoes and celeriac are tender. Once cooked, drain the potatoes and celeriac well and mash together.

2. While the potatoes and celeriac simmer, trim the roots and woody greens off the leeks. Give the leeks a rinse under a cold tap and shake them dry. Thinly slice the leeks. Peel the carrots and dice them. Tear or slice the mushrooms into small pieces. Peel and thinly slice the garlic cloves. Pick the thyme leaves off their stalks.

3. Pour 1 tbsp oil into a large pan and warm to a medium-high heat. Add the diced chicken leg to the pan, along with a pinch of salt and pepper. Fry the chicken for 5-6 mins, turning once or twice, till golden brown on all sides.

4. Slide the leeks, carrots, mushrooms, garlic and thyme into the pan. Give everything a good stir and reduce the heat under the pan to medium. Cook the chicken and veg for a further 6-8 mins, stirring often, till tender and juicy.

5. Sprinkle 1 tbsp flour into the pan. Stir well and cook for 2 mins. Pour in one-third of the chicken stock and stir well till it starts to thicken. Continue pouring in the remaining chicken stock, stirring frequently, till combined into a smooth sauce. Bring to a simmer, then take off the heat. Taste and add a pinch of salt and pepper if you think it needs it.

6. Scoop the chicken, veg and sauce into a casserole or pie dish. Top with the potato and celeriac mash. Slide the pie into the oven and bake for 30 mins, till golden brown and bubbling. Serve on its own, or with your favourite greens on the side.