Ingredients (Serves 4-6)
- 3 tbsp olive oil
- 2 large onions, peeled and finely sliced
- 1kg/21⁄4lb baking potatoes (King Edwards or Maris Piper)
- 8 eggs, gently beaten
- Salt and freshly ground black pepper
Preheat the oven to 190°C, 375°F, Gas 5.
Heat 2 tbsp of the olive oil in a frying pan over a low heat, add the onion and cook for 15-20 minutes until soft and golden.
Peel and chop the potatoes into 1cm/1⁄4in dice.
Rinse and drain in a colander then arrange in an ovenproof dish, cover and bake for 25-30 minutes until soft.
Put the eggs in a bowl, add the cooked onions and potatoes and season to taste.
Heat the remaining 1 tbsp oil in a frying pan over a medium heat. Add the omelette mixture and flatten it all out. Cook for about 15 minutes – the omelette must be firm on the base but a little runny on the top.
Remove the pan from the heat and place a large plate over it so the omelette is completely covered. Turn everything upside down so the omelette is on the plate, then carefully slide the omelette back into the pan, uncooked-side down, and cook for a further 6 minutes.
Serve straight away, cut into wedges.