375 g (12 oz) chicken breast, cut into small chunks
8 back bacon rashers, cut into pieces
2 leeks, rinsed, trimmed and cut into slices
25 g (1 oz) plain flour
300 ml (1/2 pint) milk
1 teaspoon Dijon mustard
200 ml (7 fl oz) crème fraîche
salt and pepper
green vegetables, to serve
Line a baking sheet with greaseproof paper. Cut the pastry into 4 equal rectangles or squares and place on the baking sheet so the pastry is not lying completely flat, lightly brush with beaten egg and bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 12–15 minutes until golden.
Meanwhile, heat the oil and 15 g (1/2 oz) of the butter in a heavy-based frying pan and cook the chicken and bacon over a high heat for 8–10 minutes until golden. Add the leeks and cook for 5 minutes. Remove from the heat and set aside.
Heat the remaining butter in a saucepan and add the flour. Cook for a few seconds, remove from the heat and add the milk, a little at a time, stirring well after each addition. Add the mustard, return to the heat and bring to the boil, stirring, until boiled and thickened. Add the crème fraîche and cook for 1–2 minutes. Season, then pour into the pan with the chicken and stir. Ladle the chicken onto 4 serving plates, top each with a pastry rectangle and serve with green veg.