Caviar-topped Spanish tortilla topped with a crispy fried egg

Heat the olive oil in a 20 cm high-sided pan, making sure it’s no more than a third full to stop it overflowing

Add the onions and cook until soft and beginning to caramelise – they should be a light golden colour. Remove using a slotted spoon and set aside

Add the potatoes and fry until the potatoes are completely soft. This should take around 10 minutes. Remove using a slotted spoon and set aside

Combine the onions and potatoes in a bowl and mix in 6 of the eggs. Season really well with salt - more than you might think!

Return the pan and a few tablespoons of oil to the heat and, once hot, add the tortilla mixture, swirling it around the edges to set. Turn the heat down to low and cook for 5 minutes or until just set

Carefully turn the tortilla by covering the pan with a large plate and flipping. Gently slide the tortilla back into the pan. You can now use a spatula to tuck the edges of the tortilla into the pan to give it its signature rounded shape

Cook until just set - a few more minutes - so that the warm egg oozes out when it is cut. If you prefer a more set tortilla, cook for a little longer

Heat a dash of oil in a frying pan and fry the egg to your liking. Top with caviar and chives to serve