Boil the sweet potato until the pieces are soft enough to mash. While it is cooking, sauté the onion in olive oil with the courgette and leek, all finely chopped. Once they are soft and sweet, add the mushrooms and stir for another few minutes.

Mash the sweet potato in a bowl and ad the eggs. Whisk with a fork (you can whisk the eggs separately if you want and then add, but I find that the more ingredients, the less it adds to the fluffiness of the final omelette). Add the cheese and mix well.

Finally add the pan ingredients and any others you are going to add. Wipe the pan clean and add some olive oil (about a dessert spoonful). Heat and when the oil is hot, add the omelette mix.

Put the oven on high. Leave for about 4 minutes over a moderate-to-high heat, it should be hot enough to be bubbling at the sides as in the first video. When it is cooked on the bottom and the top of the sides are starting to change colour, transfer the pan to the oven, turn on the grill, take the pan handle off and close the oven.

Leave for about 5 minutes in the oven. Instead of staying in the kitchen, I started doing something else (classic 😅), and left it a bit too long so it was a bit overdone on top. But it was still delicious! I served it with a few espárragos.