Oh boy, am I excited to share this soup with you! I’m always on the lookout for yummy foods to share on the blog, and while it sometimes takes a few rounds of trial and error before a dish is considered “blogworthy,” I knew this one was a winner right away. It’s my take on a traditional French onion soup, though it includes a few special ingredients that take the flavors over the top.
It starts out as expected with onions that are caramelized in a rich combination of butter and olive oil. To that, fresh thyme and white wine are added, bringing depth to the broth. The mushrooms seemed a welcome addition to the party of butter, onions, and wine, and although they are not typically included in French onion soup, I love how they absorb the stock and take on all its scrumptious qualities. The sourdough and parmesan cheese provide tanginess that contrasts well with the sweetness of the soup, and the smoked Gruyère, well, there’s just nothing like it. (Just make sure you aren’t like me and burn your baguette slices. But if you do, don’t sweat it – mistakes are part of the learning process!)
The taste alone is enough to keep me coming back for more, but the icing on the cake is that onions are actually very nutritious as well. They are high in fiber, vitamin C, and antioxidants and are known to help prevent cancer, promote heart health, and aid in the removal of toxins from the body. What’s not to love?
- 2 large red onions
- 2 large yellow onions
- 2 tablespoons butter
- 1 tablespoon extra virgin olive oil
- 3/4 teaspoon kosher salt
- 5-6 sprigs of fresh thyme
- 1 cup dry white wine
- 3 tablespoons unbleached all-purpose flour
- 2 quarts beef stock
- 6 cups sliced crimini mushrooms
- Kosher salt and freshly ground pepper to taste
- Sourdough baguette, cut into 1-inch slices
- 2 cups grated smoked Gruyère cheese
- 1/2 cup freshly grated parmesan cheese
- Start by trimming the root and top ends off of the red and yellow onions, then cut the onions in half lengthwise and remove the outer peel. Place the onion halves flat side down on a cutting board and slice them crosswise into ¼-inch thick half-moon shapes (four large onions should yield roughly 12 cups).
- In a large pot or Dutch oven, heat the butter and extra virgin olive oil over medium high heat until the pan is hot and the butter is melted. Add the onion slices, kosher salt, and thyme sprigs, and gently turn the onions in the pot to distribute the oil and seasonings. Cook for about 25 minutes, stirring only occasionally (be sure to allow adequate time for the onions to brown in between stirring), then pour in the white wine to deglaze the bottom of the pot. Cook for an additional 15 minutes until the onions are caramel-colored and soft. (I didn’t experience any problems cooking the onions over medium high heat, but feel free to reduce the heat slightly if needed to prevent burning.)
- Once the onions are fully cooked, stir in the flour and allow the mixture to cook for 3-4 minutes. Next, add the beef stock and sliced mushrooms, stirring to combine all the ingredients. Bring the soup to a boil, then reduce the heat to medium and let it simmer for about 20 minutes or until the mushrooms are tender. Adjust the seasoning as needed by adding additional kosher salt and freshly ground black pepper according to your taste.
- While the soup is simmering, prepare the sourdough baguette slices by placing them on a metal baking sheet under your oven’s broiler, turning once one side is golden to toast both sides.
- To assemble to soup, ladle the desired amount into oven-safe serving bowls and top with 1-2 slices of toasted baguette. Sprinkle the grated cheeses on top (roughly 1/2 cup Gruyère and 2 tablespoons Parmesan per bowl if you are making four servings) and place under your oven’s broiler until the cheese is melted and golden.
Tips and Tidbits
- This recipe calls for fresh thyme, and though it may be tempting to use the dried version for the sake of convenience and cost, I assure you it is worth the work to obtain it fresh. As soon as I added the thyme sprigs to the pot and they began to cook, their fragrance filled my home, and the soup couldn’t be done soon enough for me to devour it! The thyme totally makes this dish.
- The salt is added to the onions at the beginning of cooking not only for the sake of saltiness but also because it aids in breaking down the onions’ cell walls so that more of their natural juices and sugars are released. The result is a richer caramel taste.
- At times in my life, I’ve avoided ordering French onion soups at restaurants because the bread was often too soggy for me to enjoy. I’ve found that toasting the bread before assembling the soup, however, solves this problem. It absorbs the scrumptious juices and contributes a chewy textural element.
- To vary the recipe a bit, you could add a few other ingredients to the soup as it simmers: a bay leaf, minced fresh garlic, and/or a beef bone would all make for positive enhancements.