Put the onions and other ingredients into a thick-bottomed saucepan and cover with a tight-fitting lid. Cook for 10–20 minutes, depending on the quantity you are cooking. The onions will turn from white to translucent and the sour, raw smell will disappear and the onions will become sweet and succulent. Look at the onions from time to time to check they are not catching on the bottom – you want them cooked but not browned.
set onion base aside.
Preheat the oven to 375˚F/190˚C.
Fry the meat in the vegetable oil in a large saucepan over a high heat. Add the flour and stir well. Add the rest of the filling ingredients and combine together. Bring to the boil, cover with a tight-fitting lid, turn the heat low and cook for 1 hour or until the meat is really tender. The sauce should be thick, but not stodgy. If it is really runny, thicken it with a little cornflour mixed with cold water. Season to taste. This can be made up to 3 days ahead and stored in the fridge or frozen.
Cut the two pastry sheets into 6 equal parts so you have 12 pieces of pastry in total. Wipe the cups/bowls inside with butter and then fold the pastry and tuck and ease it in so it lines the cup. Fill the pastry with the stew and brush round the top with water (use your fingers). Cover with the other square of pastry, pressing to make sure the top and bottom are sealed. Trim with scissors leaving about 1cm edge over the bowl. Cover with a small piece of baking parchment and a layer of foil. Prepare up to 4 hours ahead.
Put the bowls into a roasting tin and cook in the oven for 1 hour. Remove and wait at least 10 minutes before serving.
To serve: Turn the puddings out onto dinner plates and serve with a large sprig of flat leaf parsley.
Lucy's cooking tips
If you buy whole kidneys, cut them in half and remove the white tubes inside. Wear latex gloves if you are squeamish.
The bowls/cups should be about 10cm in diameter and about 7cm high. If you only have small ramekins or similar, use these. Keep the rest of the stew warm and serve the pudding with a spoonful of stew on the side.
If you don’t like kidney add more meat and have a steak pudding. Alternatively, use fish pie mixture or a vegetarian pie mixture as the filling.
The lid will stop any moisture escaping so that the onions ‘sweat’ rather than fry. The small amount of water you add will help this too. If the lid does not fit well, put a layer of foil over the pan and then put the lid back on top.
If there is liquid left in the bottom of the pan, remove the lid for a few minutes so it evaporates. Stir all the time and don't let the onions brown.
Managing a budget?
• Use more kidney, less beef for extra value puddings.
• These puddings are a great way to use up leftover stews and other saucy dishes. Follow the recipe, but use your leftovers as the filling instead.
Lucy’s Food Minimum effort, maximum impact! by Lucy Cufflin, published by Hardie Grant, is out now, priced £16.99.