Heat oil in a large frying pan and sauté the onions for 30 seconds.
Add the butternut and cook for three minutes.
Add the beef and mustard, and remove from the heat.
Cut pastry into eight squares and wet the edges with water.
Place a square of pastry in an individual pie dish, spoon some filling in and top with a pastry square.
Seal the edges and cut away the rough bits.
Repeat with the remaining ingredients.
Bake in a preheated 190 °C oven for 20 minutes or until puffed and golden.
Serve with gravy, mashed potato and seasonal vegetables.
Make vegetarian pie with 200 g diced vegetables and 100 g crumbled feta cheese.