Step 1

Peel the potatoes, cut them into large chunks and put them in a saucepan of cold salted water. Bring to the boil and simmer for 15 mins until just cooked (do not overcook or the potatoes will absorb too much water).

Step 2

Meanwhile, heat 1⁄2 tbsp of the olive oil in a small pan. Add the onion, garlic and a pinch of salt, then cover and cook over a low heat for 15-20 mins until the onion is soft and starting to caramelise. If the onion starts to catch, add a splash of cold water. Remove the onion and garlic, then fry the pancetta in the same pan until the fat has melted and the pancetta is crisp.

Step 3

Drain the potatoes and allow to steam-dry. Once cool enough to handle, chop the potatoes into 1cm dice and mix in a bowl with the pancetta, gruyère, parsley, beaten eggs, onion and garlic. Season generously with black pepper.

Step 4

Heat 1 tbsp of the oil in a large non-stick frying pan. Gently tip in the potato mixture and press down with the back of a large spoon. Fry over a medium heat for 15 mins until the bottom is golden brown. Tip the hash brown onto a plate, then slide back into the pan, cooked-side up. Cook for another 15 mins until golden and hot. Serve with roasted tomatoes and mushrooms, if you like.