For the gnocchi - break up the mash so there are no lumps. Add to a bowl with the flour the egg yolk and mix together, season well and then stick together to form a dough. Roll the dough into a sausage shape.
Leave it for as long as possible. Chop into 1 centimeter gnocchi, you can reshape them too as you go. Boil in salted water for a few minutes, until they come to the surface.
Place a knob of butter with 1/2 tablespoon olive oil in a hot pan and pan fry the gnocchi for a few minutes until golden.
Add the sage and serve with grated parmesan.
For the potato cheese balls - to the leftover mashed potato whisk in the cream cheese and season. Stir through the grated parmesan. Round into balls, slightly larger than a golf ball, and tear small chunk of the mozzarella off and push into the middle of the ball. Next place the potato ball into the flour to coat, followed by the beaten egg and finally the panko. Repeat the egg and panko stages, then deep fry in frying oil at 180 until golden and crisp.
For the cottage pie - in a medium sized pan on a medium heat, heat a tablespoon olive oil and add to the onion.
Saute for a couple of minutes, add in the garlic, celery and carrot and let this cook down for about 15 minutes before breaking in the beef mince and season. Let all the meat change colour and then cover with the beef stock stir through the tomato puree and the bay leaves.
Leave to cook for as long as possible, but at least 2
Hours. Place in a suitable oven proof dish. Mix the mash with a knob of butter and season and then spoon over the mince. Place in a preheated oven 200 for about 20 minutes until golden.