Season the meat and onions with salt and pepper, add enough water (around 750ml/3 cups - you may need more, but this will be used for the gravy to serve with!) to just cover the meat and bring to the boil continuing to use the Sauté function.
Place the lid onto the Instant Pot, ensure the valve is closed. Press the "Manual" button and set the time to 60 minutes.
Beat the egg. Add a few spoons of meat onto on half of a wrap, and top with some sliced red onion - it's important not to over fill the pasties or they won't seal and may leak when cooking. Brush some beaten egg around the edge of the wrap and fold the wrap over. Press the edge down firmly with a fork and brush the top with the beaten egg.