Soufle aux épinards

03 — Method

1. Preheat the oven to 180 °C (350 °F) fan. Butter the 22 cm (9 in) soufflé dish generously, brushing upward on the sides to help it rise, then dust with grated Parmesan.
2. Wash the 600 g (21 oz) of fresh spinach in plenty of water and spin dry. Finely dice the yellow onion. Remove the germ from the 3 garlic cloves and crush them.
3. Heat 2 tbsp of olive oil in the large skillet over medium heat and soften the onion for 5 minutes. Add the garlic and cook 1 minute, then the spinach a handful at a time; cook over high heat for 5 minutes.
4. Drain the wilted spinach, pressing hard to remove all the water, then chop it very finely.
5. Make the béchamel: melt 60 g (2 oz) of butter in the medium saucepan over low heat, add the flour all at once and whisk into a roux. Cook 1 minute, then whisk in the hot milk in a thin stream and cook for 5 minutes over medium heat until thick.
6. Off the heat, stir the grated Gruyère, nutmeg, salt and pepper into the béchamel. Beat in the 8 egg yolks one at a time, whisking so they don’t cook.
7. Stir in the chopped spinach. Whip the 8 egg whites to stiff peaks with an electric whisk and a pinch of salt.
8. Whisk a third of the whites into the mixture to loosen it, then very gently fold in the rest with a spatula. Pour into the dish and bake for 30 minutes at 180 °C (350 °F).