ANNE'S TWICE-BAKED SPINACH SOUFFLéS

Steps:

• Preheat the oven to 400°F. Generously butter six 8-ounce ramekins or one 6-cup jumbo muffin tin or silicone muffin mold.
• To prepare the spinach, in a skillet, heat the oil over medium heat. Add the shallot and cook until soft and translucent, 2 to 3 minutes. Add the garlic and cook until fragrant, 45 to 60 seconds. Add the well-drained spinach and season with cayenne, salt, and pepper. Continue cooking, stirring, until the mixture is well combined and all the moisture has evaporated, 2 to 3 minutes. Set aside.
• To prepare the béchamel sauce, in a heavy-bottomed saucepan, melt the butter over medium heat. Whisk in the flour, and cook until foaming but not browned, about 1 minute. Whisk in the warmed milk. Bring to a boil over high heat. Once it is at a boil, continue cooking, stirring constantly, until the sauce thickens, about 2 minutes. Season with nutmeg, salt, and pepper.
• You will use two-thirds of this sauce as the base for the soufflés. The remaining one-third will be the coating sauce at the end. Transfer one-third of the sauce to a small saucepan. Add the half-and-half and stir to combine. Set aside.
• Stir the spinach into the larger amount of sauce; taste and adjust the seasoning with salt and pepper. Add the egg yolks one at a time, stirring between each addition. Set aside.
• To make the soufflés, in the bowl of a heavy-duty mixer fitted with the whisk, beat the egg whites with a pinch of salt on medium speed until foamy. Increase the speed to high and whip until stiff peaks form, 2 to 3 minutes.
• To lighten the soufflé, add about one-fourth of the beaten egg whites to the spinach-sauce mixture and whisk until well mixed. Pour this mixture over the remaining whites and fold together until smooth.
• Fill the prepared ramekins with the mixture. Place them on a baking sheet and bake until the soufflés are puffed and browned, 12 to 15 minutes. Leave the oven on.
• Transfer the soufflés to a rack and cool slightly. Turn out each soufflé into a large gratin dish or casserole. If the soufflés stick, release them by running a butter knife or offset spatula around the rims. Set aside.
• To finish the soufflés, bring the reserved cream sauce to a boil over medium-high heat. Add the mustard and 1/4 cup of the Gruyère cheese. Stir to combine, then taste and adjust for seasoning with salt and pepper. Spoon the sauce over the soufflés to coat, then sprinkle each evenly with the remaining 1/4 cup Gruyère. (The dish may be made to this point and held at room temperature for up to 1 hour or covered in the refrigerator for up 24 hours. However, it is important to bring the dish to room temperature before browning.)
• Bake the sauce-covered soufflés in the gratin dish until browned and bubbling, 7 to 10 minutes. Serve immediately.
• béchamel sauce
• Whether called béchamel (French), balsamella (Italian), or white sauce, this classic sauce is based on a thickener (a roux) made of butter and flour that is whisked together with milk. Simple seasonings include nutmeg, salt, and pepper, but the flavor is improved if the milk is first infused with aromatics like bay leaf and peppercorns. It is as simple as making tea: place the milk and aromatics in a pot and bring to a simmer over medium heat. Remove from the heat and let rest for about 10 minutes; strain out and discard the aromatics.
• Béchamel sauce is the workhorse of cuisine. You can change its consistency by varying the proportions of roux to milk. The more roux, the thicker the sauce, and vice versa. Thin sauces are used as bases for soups and other sauces. Add cheese, for example, and it's Sauce Mornay. A medium béchamel sauce is used for coating and in vegetarian lasagna. Thick béchamel is the base for savory soufflés.