Soufflé aux Épinards — Spinach Soufflé

Ingredients

• 500 g fresh spinach, blanched, refreshed, squeezed bone-dry, chopped very fine
• 40 g unsalted butter, plus extra for the mould
• 40 g plain flour
• 250 ml whole milk, warmed
• 4 egg yolks, added one at a time
• 5 egg whites
• 50 g Gruyère, finely grated
• 1 pinch fine salt, for the whites
• to taste salt and white pepper
• to taste nutmeg, freshly grated
• For the mould
• as needed unsalted butter, softened, for greasing
• as needed Parmesan, finely grated, for dusting

Method

1. 1
   Blanch the spinach in vigorously boiling salted water for 60 seconds. Drain and immediately refresh in iced water. Gather the spinach into a tight ball and squeeze with tremendous, sustained pressure until no further moisture can be extracted. Chop very finely or reduce to a purée. The spinach must be entirely dry — press and re-press until certain.
2. 2
   Butter the 1.5-litre soufflé dish generously, then dust the interior with finely grated Parmesan, tapping out the excess. Refrigerate the prepared dish until required. Heat the oven to 190 °C.
3. 3
   In a saucepan over medium heat, melt 40 g of butter. Add the flour and cook the roux, stirring constantly, for 2 minutes without allowing it to colour. Add the warm milk gradually, whisking continuously until the béchamel is thick and smooth. Remove from the heat. The finished base should fall from a spoon in a slow, heavy ribbon.
4. 4
   Off the heat, beat the dried spinach into the béchamel. Add the egg yolks one at a time, beating each fully into the base before adding the next. Stir in the grated Gruyère, salt, white pepper, and nutmeg. The base should be thick, smooth, and intensely green. This stage may be completed hours in advance; bring to room temperature before proceeding.
5. 5
   This is where the dish lives or dies: whisk the 5 egg whites with a pinch of salt to stiff, glossy peaks — firm enough to hold their shape but not dry or grainy. Fold one-third vigorously into the spinach base to lighten it. Add the remaining whites in two gentle additions, using broad, deliberate strokes to preserve every particle of volume. Fold only until no white streaks remain; a single stroke too many costs the rise.
6. 6
   Pour the mixture into the prepared dish to three-quarters of its depth. Run the tip of the thumb cleanly around the inside rim to create a shallow channel — this encourages the characteristic top-hat rise. Place immediately on the oven's middle shelf.
7. 7
   Bake at 190 °C for 25–28 minutes without opening the oven door at any point. The soufflé is ready when it has risen 5–7 cm above the rim, the surface is golden, and the centre retains a gentle, visible wobble when the shelf is carefully nudged. Carry to the table and serve within 60 seconds.