- 1 tbsp olive oil
- 1 large onion, finely chopped
- 3 thyme sprigs, leaves picked
- 2 garlic cloves, crushed
- 350g chicken breasts, cut into small chunks
- 250g chestnut mushrooms, sliced
- 300ml chicken stock
- 100g crème fraîche
- 1 tbsp wholegrain mustard
- 100g kale
- 2 tsp cornflour, mixed with 1 tbsp cold water
- 375g pack puff pastry, rolled into a circle slightly bigger than your dish
- 1 egg yolk, to glaze
- Heat 1/2 tbsp oil over a gentle heat in a flameproof casserole dish. Add the onion and cook for 5 mins until softening. Scatter over the thyme and garlic, and stir for 1 min. Turn up the heat and add the chicken, frying until golden but not fully cooked. Add the mushrooms and the remaining oil. Heat oven to 200C/180 fan/gas 6.
- Add the stock, crème fraîche, mustard and kale, and season well. Add the cornflour mixture and stir until thickened a little.
- Remove from the heat and cover with the puff pastry lid, pressing into the sides of the casserole dish. Slice a cross in the centre and glaze with the egg. Bake for 30 mins until the pastry is puffed up and golden.