Tortilla are often made with variety of ingredients - chopped red or yellow (bell) peppers, cooked peas, corn, or grated cheese. Gruyere cheese can all be added to the mixture in Step 2, if you like.

800 g or 1 3.4 medium potatoes
2 onions, thinly sliced
6 eggs
100 ml or 3 1/2 fl oz or scant 1/2 c EVOO
Salt and ground black pepper

800 g or 1 3.4 medium potatoes 2 onions, thinly sliced 6 eggs 100 ml or 3 1/2 fl oz or scant 1/2 c EVOO

1. Thinly slice the potatoes. Heat 5 tbs of the oil in a frying pan and cook the potatoes, turning frequently, for 10 minutes. Add the onions and seasoning, and continue to cook for a further 10 minutes, until the vegetables are tender.

2. Meanwhile, beat the eggs in a large bowl with a little seasoning. Tip the potatoes and onions into the eggs and mix gently. Leave to stand for 10 minutes.

3. Wipe out the pan with kitchen paper and heat the remaining oil in it. Pour the egg mixture into the pan and spread it out in an even layer. Cover and cook over a very gentle heat for 20 minutes, until the eggs are just set. Serve and cut into wedges.