Preheat your oven to 200°C (400°F) convection heat.

Have a nonstick 24 cm (9.5 in) frying pan ready, as well as a stand or electric mixer to beat the egg whites.

Separate and measure the egg whites and yolks into separate bowls.

In a medium-sized bowl, add the egg yolks, sugar, and 10 ml (0.3 fl oz) Cointreau (or any liqueur you use), then whisk vigorously for 2 minutes until the mixture is whitish and almost foamy.

Add the egg whites, salt, and lemon juice to the mixer bowl and whisk on medium speed until the egg whites double in volume.

Add the sugar, then raise the speed of the mixer and beat the meringue until it forms stiff peaks.

Add 2 tablespoons of meringue to the sugar and egg mixture and combine gently with your whisk.

Use a spatula to carefully fold the rest of the meringue into the egg and sugar mixture.

Add the butter to your pan over high heat, and as soon as the butter starts to foam, pour all the soufflé mixture into the pan and flatten the top.

Put a lid on and immediately reduce the heat to low, and leave to cook for 2 to 3 minutes.

After 3 minutes, remove the pan from the heat and slide half of the omelette onto a buttered plate, then fold the second half over itself.

Transfer the plate to the oven and leave to cook for 3 to 5 minutes.

Warm up the rest of the liqueur in a small saucepan, avoiding any boiling, then set it aside ready for the flambé.

Take the omelette out of the oven and serve directly on the table.

Ignite the warm liqueur and pour it over the omelette for a dramatic flambé.

As soon as the flames subside, dig in!