Step 1

Spray a large frying pan with low calorie cooking spray and place over a medium heat. Add the onion and fry for 10 - 15 minutes, stirring occasionally, until softened and golden.

Step 2

Add the garlic and chicken and seal for 1-2 minutes on all sides.

Step 3

Add the mushrooms, chicken stock, Dijon mustard and mustard powder. Stir, then simmer uncovered, for 25 - 30 minutes until the sauce has reduced slightly. The chicken should no longer be pink inside, and the juices should run clear. Remove from the heat and stir in the cream cheese until completely blended. Stir in the spinach until just wilted. Taste the sauce and season to taste with salt and pepper if needed.

Step 4

Pre-heat the oven to 180 ºC. While the chicken is cooking, place the potatoes in a large saucepan of water. Cover with a lid, bring to the boil, then lower the heat. Simmer, partially covered, for 20 minutes until tender.

Step 5

Drain the potatoes well and return to the saucepan. Mash the potatoes with the milk until smooth. Season to taste with salt and pepper. Cover with the lid and set aside.

Step 6

Place the pie filling in an 18 x 27cm ovenproof dish and spread out evenly.

Step 7

Place the mashed potato on top and spread over the filling. Use a fork to texture the surface.

Step 8

Sprinkle with grated Cheddar cheese and place on a baking tray.

Step 9

Place in the preheated oven for about 20 minutes or until golden and piping hot all the way through.

Step 10

Serve with steamed vegetables.