Step 1

Chop the spinach leaves and thin stems into tiny pieces. Heat the butter in a large saucepan and slightly golden the onion.

Step 2

Add the garlic and let it fragrant; add the spinach, a pinch of salt, and keep it in high heat for about 5 minutes until the leaves are tender and the liquids have dried up. Set it aside.

Step 3

In a medium-sized pan, heat the butter and flour, mixing nonstop with a whisk, making sure to scrape the bottom as well. When you obtain a white roux, add the milk, salt all at once and, mixing nonstop, let it cook for about 5 minutes until it boils and thickens. Still whisking nonstop, add the mustard, pepper, nutmeg, and salt and cook for 5 minutes more, until flavorful. Turn off the heat, mix in spinach and let it cool for 15 minutes.

Step 4

Meanwhile, heat the oven to 420ºF/210ºC (high).Using a brush, grease 6 soufflé ramekins (6 oz) with butter, wait for 5 minutes, grease them again, dust the breadcrumbs and take them to the fridge for 10 minutes.

Step 5

With a blender, beat the egg whites until medium-stiff peaks.

Step 6

Mix the cheese and egg yolks to the creamy spinach. Place 1/3 of the egg whites into the bowl and mix with a spatula to make it lighter.

Step 7

Mix with the spatula on a movement of cutting the cream up to the bottom of the bowl and lifting up, gently fold the remaining egg whites.

Step 8

Divide between the prepared ramekins, clean the edges and place them on a baking sheet. Place the baking sheet in the middle of the oven and the soufflé for 10 minutes.

Step 9

Turn the heat down to 350Fº/180ºC (medium) and bake for 10 minutes more, until it’s cooked and firm and golden on the outside.

Step 10

Serve immediately.