Serves 8 – Prep: 1h 15min – Oven: 20 minutes

Peel and quarter the potatoes. Put into a large saucepan with salted water, cover and bring to the boil, then cook for 15 minutes until soft.

Meanwhile, trim the leek and discard the green tops. Finely slice, put in a colander and wash under a running tap. Set aside.

Cut the chicken into bite-sized chunks and set aside.

Cook the peas in boiling salted water for 2 minutes, drain and set aside.

Put a tablespoon of oil in a large, deep frying pan and fry the bacon lardons for a few minutes until browned. Put in a big mixing bowl. Add another tablespoon of oil to the pan and fry the chicken pieces with a pinch of salt and pepper until browned. Add to the bowl with the bacon.

Melt the butter in the pan used for the meat and fry the leek for approximately 8 minutes until soft. Peel and crush the garlic clove and fry with the leek for another minute. Stir the flour through the leeks, then add the white wine and cook for a minute. Gradually add the milk, stirring between additions to thicken. Once all the milk is used up, stir through the two mustards. Season to taste with salt and pepper, then pour the sauce into the bowl with the chicken. Add the cooked peas and stir to combine.

Put the chicken filling into a large baking dish measuring approximately 40 x 25 cm.

Preheat the oven to 180°C fan.

Once the potatoes are soft, drain and mash the cooked potatoes. Add the butter, Kachkéis and milk and season to taste with salt and pepper.

Put the mash into a piping bag fitted with a round nozzle and pipe the mash all over the warm chicken filling.

Drizzle a bit of melted butter over the mash, then bake the pie in the preheated oven for 20 minutes until the filling is bubbling and the mash is golden.