Prepare to be amazed by the most elegant, cloud-like dish you’ll ever make from a handful of simple onions. This Savory Onion Soufflé is a true showstopper, rising majestically from its dish with a golden-brown crust that gives way to a ridiculously light, airy, and creamy interior. The flavor is a revelation—deeply savory with the subtle, caramelized sweetness of onions, enriched with Parmesan and a hint of nutmeg. It sounds fancy, but trust me, it’s a straightforward and magical process. Perfect for a special brunch, a light lunch, or an impressive starter for your next dinner party!
Ingredients
• 6 medium onions, about 1½ lbs / 680g
• 4 Tbs. unsalted butter, 2 oz / 57g, plus more for the dish
• 4 Tbs. all-purpose flour, about 1 oz / 30g
• Just under ½ cup heavy cream / 120 ml
• ½ tsp. salt / 2.5g
• Freshly ground white pepper to taste
• 1 dash of ground nutmeg
• 1 dash of cayenne pepper
• 2 Tbs. grated Parmesan cheese, about 0.35 oz / 10g, plus more for the dish
• 4 large egg yolks, room temperature
• 5 large egg whites, room temperature
• 1 pinch of cream of tartar
• Light tomato sauce, for serving
Instructions
1. Prepare the Onions: Peel all the onions. Quarter 5 of them and place them in a pot with enough lightly salted water to cover. Bring to a boil and cook until completely tender, about 15-20 minutes. Drain the onions, reserving ⅓ cup / 80 ml of the cooking water. Mince the cooked onions finely. Finely chop the remaining raw onion.
2. Make the Soufflé Base: In a medium, heavy-bottomed saucepan over medium heat, melt the 4 Tbs. of butter. Add the finely chopped raw onion and sauté until softened and just beginning to turn golden. Lower the heat, stir in the flour, and cook for 2 minutes, stirring constantly with a wooden spoon to create a roux. Slowly whisk in the reserved ⅓ cup of onion water and the heavy cream. Continue stirring over low heat until the mixture is perfectly smooth and very thick.
3. Flavor the Base: Remove the saucepan from the heat. Stir in the minced cooked onions, salt, white pepper, nutmeg, cayenne, and the 2 Tbs. of grated Parmesan cheese. Quickly whisk in the egg yolks one at a time until the mixture is smooth and glossy.
4. Fold in the Egg Whites: In a separate, spotlessly clean bowl, beat the egg whites and cream of tartar with an electric mixer on high speed until they form stiff, shiny peaks. Stir about one-quarter of the beaten egg whites into the onion base to lighten it. Then, gently fold in the remaining whites in two additions with a rubber spatula, being careful not to overmix and deflate the batter.
5. Bake the Soufflé: Generously butter a 2-quart soufflé dish. Carefully pour the soufflé mixture into the prepared dish. Place it in a preheated 350°F / 175°C oven and bake for 35 to 40 minutes, or until the soufflé is puffed, golden brown, and set. Do not open the oven door for the first 30 minutes. Serve immediately with a light tomato sauce on the side.
Nutritional Information
• Serving Size: 1 of 6 servings. Calories: 265 kcal. Protein: 10g. Fat: 20g. Carbohydrates: 11g. Sodium: 350mg. *Please note these are good-faith estimates and can vary based on used.
Pro Tips
• for the Perfect Soufflé
• For an extra lift, after buttering your soufflé dish, coat it with a fine layer of grated Parmesan cheese. This gives the batter something to grip onto as it rises.
• Ensure your egg whites and yolks are at room temperature before you begin. Room temperature whites will whip up to a much greater volume, giving you a lighter soufflé.
• Use a spotlessly clean, dry bowl to beat your egg whites. Any trace of fat, grease, or egg yolk will prevent them from reaching their full, lofty potential.
• Resist the urge to peek! Opening the oven door, especially during the first 30 minutes of baking, can cause a sudden temperature drop and make your beautiful soufflé collapse.
• Soufflés wait for no one! Have your guests seated and ready to eat the moment it comes out of the oven, as it will begin to deflate within minutes.
FAQ
Q: Can I make this onion soufflé gluten-free
A: Yes, this recipe can be easily adapted for a gluten-free diet. Simply substitute the all-purpose flour with your favorite 1-to-1 gluten-free baking flour blend when making the roux. The rest of the ingredients are naturally gluten-free.
Q: Is this vegetarian soufflé a good source of protein
A: With approximately 10g of protein per serving from the eggs and Parmesan cheese, this soufflé is a satisfying vegetarian dish. To create a more protein-rich meal, consider serving it alongside a hearty lentil salad or a quinoa side dish.
Q: Can I prepare this savory soufflé in advance
A: While soufflés are famously best served immediately, you can do some prep work. The onion base (steps 1-3, before adding eggs) can be made up to a day ahead and stored, covered, in the refrigerator. When ready to bake, gently warm the base to room temperature before whisking in the yolks and folding in the freshly beaten egg whites.
Q: What vegetarian main course goes well with this onion soufflé
A: As an impressive starter, this soufflé pairs beautifully with a main course like a mushroom and spinach risotto, a hearty root vegetable tart, or a simple pasta with a vibrant pesto sauce and roasted cherry tomatoes.
