Step by step recipe:

1. 5 min.
   Break 6 eggs into a bowl, add salt and pepper then beat with a whisk.
2. 7 min.
   Peel 300 g cooked potatoes and slice.
   
   Prepare 1 onion and chop finely.
3. 7 min.
   Pour 4 tablespoons oil into a large frying pan on high heat.
   
   When really hot, add the sliced potatoes and brown on both sides.
   
   Salt after frying and set aside.
4. 3 min.
   Use the same pan to fry 150 g small pieces of bacon until lightly browned.
5. 2 min.
   Then add the chopped onion and cook for a further 2 or 3 minutes without browning the onion.
   
   Check the seasoning.
6. 2 min.
   Preheat the oven to 360°F (180°C).
   
   Butter a gratin dish, then add the potatoes and spread the bacon and onions over the top.
7. 1 min.
   Pour the beaten eggs over.
8. 25 min.
   Bake for about 25 minutes. Check towards the end to ensure that the omelette is not overcooked.
9. 
   Serve without delay.