• 1 kg (2 lb 4 oz) floury potatoes
• 1 brown onion, finely diced
• 1 garlic clove, very finely chopped
• about 1 litre (35 fl oz/4 cups) olive oil
• 8 eggs
• sea salt flakes
• 60 ml (2 fl oz/¼ cup) olive oil, extra

Cut the potatoes into paper-thin slices using a mandolin or a very sharp knife and then cut into 1 cm (½ inch) squares.

In a large heavy-based frying pan confit the potato, onion and garlic. To do this, cover them with the olive oil and heat over high heat until the oil just starts to warm then reduce the heat to low–medium and cook for 30–35 minutes. You should only be able to see very fine bubbles occasionally — it should not be rapidly bubbling. The idea is to soften the potatoes but not turn them into little chips. As the potato cooks, use the back of a large spoon to break them up into smaller pieces. After 30–35 minutes try a piece, it should be very soft to touch.

When done, put the potato mixture in a chinois or fine sieve and drain the oil. The oil can be strained and used another three or four times to confit other dishes in this book.

Meanwhile, in a large bowl gently whisk the eggs until smooth and mix in 1 teaspoon salt. Reserve 185 ml (6 fl oz/¾ cup) of the egg mixture in a separate bowl. Add the potato mixture to the egg mix in the bowl and briefly mix. Season with sea salt flakes to taste. Heat the extra olive oil in a 28 cm (11¼ inch) non-stick frying pan over medium–high heat. Pour in the egg and potato mixture. As the mixture starts to thicken shake the pan in a circular motion — the edges should start to round. Using a wooden spatula, start shaping the mixture into a thick disc that is rounded at the edges like a fat Frisbee. After 1 minute cover the frying pan with a plate or round flat tray, and quickly flip the plate and pan so the tortilla is on the plate. Gently slide the tortilla back into the pan, uncooked side down, and reduce the heat to low–medium.

Smooth out any imperfections in the cooked surface of the tortilla by pouring over a little of the reserved beaten egg and smoothing it in with a wooden spoon. Cover and cook for 2 minutes. Flip the tortilla again and repeat the smoothing process with some of the remaining beaten egg on the freshly exposed side. Cover and cook for a further 2 minutes. Repeat the process then cover and cook for 2 minutes.

Flip the tortilla, pour on any remaining egg mix, smooth, cover, and cook for 1 minute. Flip and cook, covered, for a further minute.

When done the tortilla should not be completely firm and should have a little wobble in it when you gently shake the pan. Remove from the heat and keep in the pan in a warm place for 5 minutes. Slide onto a plate and cover with plastic wrap for 5 minutes. This allows the residual heat to set the remaining uncooked egg without the interior becoming rubbery. Serve at room temperature.