Roast the potatoes at 180 degrees celsius for 50 minutes. Remove, allow to cool slightly and peel.
Add them to a mixing bowl with the flour and mash together well or use a potato ricer and mix well.
Mix in the salt and parmesan. Mix in the egg with a fork at first before bringing everything together with your hands until you have a soft, smooth dough.
Divide into 4 pieces and roll each piece on a floured surface into a snake shape with your hands that is about a centimetre thick. Then cut is into 2 centimetre segments and set aside until later making sure they are well floured so they won't stick together.
Bring a large pot of salted water to the boil as you melt the butter and oil together in a large frying pan until foaming. Add the diced onion and allow to cook for a few minutes over a medium heat.
Add the garlic and oregano leaves. Stir and cook for a minute before you add your chopped mushrooms and chilli flakes. Clamp the lid on and cook for 10 minutes over a medium low heat.
Stir in the sun-dried tomatoes and diluted tomato puree. Clamp the lid on again and allow to cook for another 5-6 minutes.
As that is cooking, the salted water should be boiling so drop in the gnocchi. Give them a gentle stir to stop them from sticking and allow them to boil for about 4 minutes or you will know they are done when they all float to the top of the cooking water.
Take a mugful of the starchy cooking water to add to the sauce later to loosen it and strain the gnocchi.
Now remove the lid from the sauce, stir, add the gnocchi and mix.
Mix in the reserved starchy cooking water and check and adjust the seasoning.
Plate up and scatter over about a tbsp of grated parmesan and some chopped, fresh basil and drizzle over a little extra virgin olive oil.