The first time I tasted Brennan’s French onion soup in New Orleans, I was captivated by its unexpected richness. Unlike any version I’d had before, this soup had a velvety texture and depth that lingered pleasantly. When the server revealed the secret was a liaison of egg yolk and cream added at the end, I knew I had to recreate this experience at home.
Brennan’s Restaurant has been a cornerstone of New Orleans cuisine since 1946, seamlessly blending French culinary traditions with local Creole influences. While many restaurants serve French onion soup, Brennan’s version stands apart by forgoing the traditional wine or sherry in favor of an egg and cream finishing touch that transforms this humble dish into something truly extraordinary. The result is a soup with a remarkable body and luxurious mouthfeel that maintains the sweet caramelized onion flavor. This elegant yet comforting dish exemplifies the sophisticated comfort food that has made Brennan’s a beloved institution for generations.
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What Makes Brennan’s French Onion Soup So Good?
In a city that prides itself on culinary tradition, Brennan’s Restaurant stands out as one of those stalwart establishments that embodies classic New Orleans charm. Since its founding in 1946, the restaurant has become a must-visit destination for locals and tourists alike seeking authentic Creole-French cuisine in an elegant setting.
While Brennan’s serves a wide selection of upscale French and Creole-inspired dishes, its unique interpretation of French onion soup has captivated diners for decades. What sets Brennan’s version apart is its departure from conventional ingredients like wine and sherry, instead incorporating eggs and cream to create an incredibly decadent, silky texture that transforms this humble dish into a luxurious experience. This unexpected twist has become a signature element that exemplifies Brennan’s approach to refined comfort food.
Why You Should Try This Recipe
The science behind this exceptional soup lies in the unique liaison technique. Traditional French onion soup relies on the long, slow caramelization of onions to develop flavor and body. Brennan’s version enhances this foundation with a classic French culinary technique called “liaison,” which introduces fat and protein from egg yolks and cream to create a velvety texture without diluting the flavor. The egg proteins gently thicken the soup while the fat in both ingredients adds richness and a silky mouthfeel. The absence of wine or sherry, common in traditional recipes, allows the sweet onion flavor to shine more prominently and creates a more approachable flavor profile. Finally, the contrast between the smooth, creamy soup, the crisp bread, and the melted cheese topping creates a perfect textural balance that makes each spoonful a delight.
Brennan’s French Onion Soup Ingredients
For this unique take on French Onion Soup, you’ll need the following:
- Sweet onions – Form the foundation of the soup with their natural sweetness
- Unsalted butter – Provides richness and helps caramelize the onions
- All-purpose flour – Helps thicken the soup slightly
- Beef stock – Creates the savory base of the soup
- Cayenne pepper – Adds subtle warmth and depth
- Salt – Enhances all flavors
- Egg yolk – Creates the unique silky texture that defines this soup
- Heavy cream – Works with the egg yolk to create a luxurious mouthfeel
- French bread – Provides textural contrast as a floating garnish
- Parmesan cheese – Adds savory notes and creates the classic broiled topping
- Breadcrumbs – Offer additional textural contrast when mixed with butter
Ingredient Notes and Substitutions
With their slightly sweet flavor, Vidalia onions are an excellent choice for making French Onion Soup. Walla Walla onions are another good option. If you can’t find sweet onions, try using white onions with a pinch of sugar.
Substituting light or half & half for the heavy cream in this recipe won’t work. You need the fat content to thicken the soup without separating.
Substituting olive oil for the butter won’t work either. You need the butter’s creaminess and flavor.
You can swap croutons or sauteed breadcrumbs for slices of French bread if you prefer.
If desired, you can substitute the Parmesan cheese with Swiss or Gruyere.
Add two bay leaves to the soup for additional flavor. Remember to remove them before serving the soup.
How to Make Brennan’s French Onion Soup
To prepare Brennan’s French Onion Soup:
- Cut the onions into paper-thin slices. Use a mandolin if you have one; just be careful and use the food guard that came with it.
- Melt the butter in a large soup pot on the lowest setting on your stove. Add the onions and stir well to coat in the butter.
- Cook the onions on very low heat until the onions start to break down. Stir occasionally.
- Sprinkle the flour over the onions and stir it in.
- While the onions are cooking, melt butter in a small bowl in the microwave. Add the bread crumbs and stir to coat with the melted butter.
- Transfer the bread crumbs to a small oven-safe dish, and bake for about 10 to 12 minutes, until they begin to brown and become fragrant. Remove from the oven and set aside
- Continue to cook and stir the onions for 10 to 15 more minutes before pouring in the beef stock and adding the cayenne pepper and salt.
- Bring the soup to a boil and reduce it to a simmer for 15 more minutes. Stir from time to time.
- While the soup is simmering, use a whisk to blend the egg and heavy cream together in a small bowl. Reserve for later.
- Remove the pot from the heat.
- Temper the egg and cream mixture by adding a few tablespoons of the hot soup to the bowl while whisking. Raising the temperature will help to prevent the egg from scrambling when you add it to the rest of the soup.
- Pour the warmed egg and cream mixture into the soup pot and stir well. This step, called a Liaison Finale in French, quickly thickens soups and sauces without adding starch.
- You can keep the soup warm in a soup kettle, crock pot, or over low heat.
- To serve, preheat the oven to broil and ladle the soup into oven-safe bowls. Place the bowls on a baking sheet.
- Float slices of French bread on the soup and top the rounds of bread with parmesan cheese and buttered bread crumbs. Melt the cheese under the broiler flame.
- If desired, garnish the soup with fresh thyme leaves or other fresh herbs.
What to Serve It With This New Orleans French Onion Soup Recipe
This soup is pretty rich, so it’s a good idea to pair it with something that’s on the lighter side. An entree salad is a great choice; perhaps a Cobb salad, spinach salad with warm bacon dressing, wedge salad with blue cheese dressing, or Chicken Caesar salad. Baked white fish or poached fish is also a good option.
If you are really hungry, then go ahead and make a classic Steak Frites for an authentic French experience.
How to Store French Onion Soup
If possible, eat this soup the same day you make it. Although you can save leftovers for a few days in an airtight container in the fridge, due to the egg and cream in it, the soup will likely get clumpy and won’t reheat well.
So, if you plan to make the soup in advance, stop preparing the recipe before adding the egg and cream. It will reheat much better.
What’s the Best Way to Reheat French Onion Soup
To reheat a soup already thickened with egg and cream, pour it into a saucepan and add some beef stock or water to thin it out. Heat it gently over medium-low heat while stirring constantly. Garnish the soup with the sliced bread and cheese and finish it in the oven as above.
If you didn’t add the liaison, simmer the leftovers in a medium saucepan, and thicken the soup with egg and cream as described in the recipe. Finish the recipe as stated.
Brennan’s Creamy French Onion Soup with Egg Liaison
Ingredients
- 16 ounces butter divided use
- 4 cups sliced onions
- 1 cup bread crumbs
- 1 3/4 cups all-purpose flour
- 12 cups beef stock
- 1/2 teaspoon cayenne pepper
- 1 1/2 tablespoons salt
- 1 egg yolk
- 2 tablespoons cream
- 8 slices French bread toasted
- ½ cup grated Parmesan cheese
Instructions
- In a 6-quart soup pot, melt 12 ounces of butter. Add the onions and reduce the heat to very low, ensuring that the onions do not brown. Cook until the onions have caramelized.
- While the onions are cooking, preheat the oven to 350°F.
- Melt 4 ounces of butter in a small bowl in the microwave for about 30 seconds on high power. Add the bread crumbs and stir to coat with the melted butter. Transfer the bread crumbs to a small oven-safe dish, and bake for about 10 to 12 minutes, until they begin to brown and become fragrant. Remove from the oven and set aside.
- When the onions have caramelized, add the flour to the pot and cook for 5 to 10 minutes, stirring occasionally.
- Add the stock, cayenne, and salt and bring to a boil. Reduce the heat and simmer for about 15 minutes. Remove the pot from the heat.
- Beat the egg yolk and cream in a small bowl. Add a little of the soup to the bowl and mix quickly. Then add the egg mixture to the soup pot.
- Ladle the soup into small bowls, place a piece of toasted French bread over each bowl, and sprinkle with the grated Parmesan cheese and buttered bread crumbs. Place the bowls under the broiler until the cheese melts and begins to brown. Serve immediately.
Nutrition
More Brennan’s Copycat Recipes
Love onion soup? Try these great recipes!
- Applebee’s French Onion Soup
- Panera French Onion Soup
- Onion Soup Gratinee
- Outback Creamy Onion Soup
- TGI Friday’s French Onion Soup
Favorite Soup Recipes
- Chicken Gnocchi Soup
- Chili’s Chicken Enchilada Soup
- Cream of Celery Soup
- Creamy Vegetable Soup
- Panera Autumn Squash Soup
Check out my easy soup recipes and the best copycat restaurant recipes on CopyKat!
Just finished a wonderful bowl of this soup. Was easy to follow the instructions and this is a keeper!
Again I love onion soup! This one looks good I’ll have to try it!