Ingredients

• 750g/1¼lb potatoes, peeled and very thinly sliced
• 2 red onions, peeled and sliced
• 6 tablespoons olive oil
• 100g/4oz Gruyère cheese, grated
• 2 tablespoons fresh basil, chopped
•   salt
•   black pepper

Method

1. Peel the potatoes and slice very thinly with a mandolin or sharp knife. Place them in a bowl and cover with cold water. Allow to stand for about 10 minutes. Drain on kitchen paper.
2. Peel and slice the onions. Heat the oil in a large frying pan over a medium heat. Add the onions and sauté for 2 minutes. Add the potatoes and cook for 15-20 minutes, turning frequently, until they are tender and golden.
3. Grate the Gruyère cheese. Add the basil to the pan and stir in. Sprinkle the cheese over the top and cook for 2 minutes, without stirring, until the cheese melts. Season and serve.