Simply Complex
Bistro French onion soup is something I order frequently at restaurants. Regardless of where I order this soup, the constants are beef broth, onions, croutons, and melty cheese in some type of mini crock. Maybe because of the presentation I’ve thought of making Bistro French Onion Soup with Bourbon as being a little bit of an intimidating dish.
The first goal for my Bistro French onion soup with Bourbon recipe is to build a complex, rich flavor and heavy beef broth. Secondly, achieve this desired flavor with simplicity and speed. My version has soft onions, not pureed, and takes only about 35 minutes to cook. Keep it simple.
What You Need to Make Bistro French Onion Soup
- Sweet Onions – I love onions. There, I said it. Frequently, I have an abundance of onions in my pantry… and cheese in the fridge. I love onions. Raw onions give dishes a bite and crunch. Cooked onions transform into a sweet, tender, flavorful component. You can see the transformation from raw onions with just butter, salt and rosemary to a caramelized onion to a deep gravy like mix.
- Butter and Olive Oil – I use both, the butter adds richness and fat. The oil has a higher burn point so it can handle the heat.
- Rosemary – Fresh is best, it will add flavor and an amazing aroma.
- Balsamic Vinegar – Find a good quality vinegar. You want it to be thick like molasses, not watery and thin.
- Bourbon – Use what you like, you can omit this as well, but it definitely adds a great flavor.
- Oranges – Add a little sweetness and citrus to the flavor.
- Beef Broth – Essential to the soup. You want this ingredient to be dark and rich looking like coffee, not a thin tea. I recommend making broth from a bouillon paste, this way you can add more and concentrate the flavor.
- Cheese! – Mozzarella and provolone, both excellent melting cheeses. Using the broiler will give you a restaurant quality bubble to your cheese.
- Bread – Hidden under the bubbly cheese, making a barrier for the soup are crunchy homemade croutons.
How To Make Bistro French Onion Soup with Bourbon
What makes this soup so great? It’s all in one… a delicious broth, topped with bread and melted cheese. To make French onion soup with Bourbon, it’s all about a slow cook over low heat. With just a few sugary liquids to help the caramelization process, the hard work is to keep stirring.
Making your own croutons is easy. The key is to find a sturdy bread like French or even sourdough. Day-old bread will work well and it’s a great way to avoid food waste. Cut the bread into generous, thick cubes and toss with oil and salt. Briefly pan fry and add to the soup. Croutons will still soak up the broth but will hold their shape.
To make salad croutons, follow these same steps but add a few spices like oregano or basil and a bit of garlic powder.
Creme de la Creme
For me, the creme de la creme of French onion soup with Bourbon is the cheese on top. The golden bubbly cheese cap on top that begs for a spoon. Gruyere is often used in this recipe. But that’s not what I often have in my fridge. I used shredded mozzarella and sliced provolone. I actually found a smoked provolone but was disappointed the smokey flavor just wasn’t strong enough. Swiss cheese could be nice too. Use what you have.
Tips, Tricks, & FAQs
- Short Cuts. The preferred method to heat the cheese, of course, is to broil. But, the next day, if I’m in a hurry, I definitely heat everything in the microwave. It’s not as pretty, but it saves a few minutes, and it tastes nearly as good.
- Find a Quality Balsamic Vinegar. Please, please find yourself a good balsamic vinegar. I really didn’t appreciate the difference between the cheap vinegar and the pricier kind until I had really good vinegar. It will be worth it. I’m now a vinegar snob. It’s also not something I use all the time, so my favorite has lasted me quite a while. Please spend just a bit more to get a quality ingredient.
- Paste, Liquid, or Bouillon Broth. Let’s talk about the broth. Find what works for you. As I made the soup, I switched from one type of beef paste to a bouillon powder. I could have intensified the onion mix all day long, but the thin ‘tea’ like broth was going to dilute all that flavor. Canned or boxed pre-made broth will likely work too. Again, test and try. Find what you like.
- Using Ramekins for French Onion Soup. Ramekins are small oven safe bowls for French onion soup. These are small but can come in a few diameters and depths. I don’t use my ramekins a lot, but they are in my top 20 list of items I love in my kitchen. They really bring home the restaurant feel.
Bistro French Onion Soup with Bourbon
Equipment
- 4 – 4" deep soufflé ramekins or other oven safe bowls
- baking sheet
- Cast iron skillet or other pan
- chef's knife
- cutting board
- Dutch oven or other large pot
- measuring cups
- measuring spoons
- mixing bowl
Ingredients
- 2 large sweet onion (16 oz)
- 2 tablespoons salted butter (1/4 stick)
- 2 tablespoons olive oil
- 1/2 teaspoon sea salt (1/4 teaspoon for onions, 1/4 for bread)
- 2-3 4" sprigs rosemary
- 1 loaf French bread
- 1 teaspoon high quality balsamic vinegar (thick like molasses, not watery)
- 2 tablespoons of your favorite Bourbon whiskey
- 1 tablespoon orange juice
- 3 1/2 cups beef broth (dark like coffee, not like tea)
- 1 cup shredded mozzarella cheese
- 4 slices provolone cheese (circle slices)
Instructions
Onions
- Slice. Start by cutting the tops and ends off the onions. Then, slice the onion in half at the midway point between top and end. This should make it easier to peel off the outside dry layers.2 large sweet onion (16 oz)
- Chunks. Next, cutting in the direction of the rings, slice each onion half into ½” thick slices. Finally, keeping the half onion together, cut the strips to 1-1 1/2” chunks. The goal is to end up with somewhat even sized pieces about the size of quarters, not stringy, thin onions.
- Set Aside. Place the cut onions in a bowl and set aside.
- Butter. Melt butter in Dutch oven pot over medium heat, about 1 minute.
- Cooking. Place the onions and salt in the pot. Stir to coat the onions. Add rosemary.2-3 4" sprigs rosemary, 2 tablespoons salted butter (1/4 stick)
- Tender Goodness. Cook onions over low heat for 20 minutes, stirring occasionally. Once the onions begin to turn golden-brown, stir more frequently to keep onions from burning. Onions will begin to get translucent and soft, but still have a little crunch. Brown bits of goodness should start to form on the bottom of the pan and the rosemary should be fragrant.
While the onions cook, prepare the croutons:
- Bread. Cut bread into 1” cubes, about 6 cubes per serving, and place in a bowl.1 loaf French bread
- Olive Oil and Salt. Drizzle the cubes with 2 tablespoons of olive oil and ¼ teaspoon salt. Toss to coat cubes.2 tablespoons olive oil, 1/2 teaspoon sea salt (1/4 teaspoon for onions, 1/4 for bread)
- Toasty. Heat a cast iron skillet or pan. Cook bread cubes over medium heat, 2-3 minutes in total turning to toast the other sides. (This doesn’t have to be perfect. Let the bread toast, toss them around and cook a bit longer – don’t worry about trying to tediously turn all cubes to get all 4 sides).
Back to the onions…
- Remove Rosemary. Remove the rosemary from the onion mix.
- Liquids. Add the balsamic vinegar, Bourbon whiskey and orange juice to the onions.1 teaspoon high quality balsamic vinegar (thick like molasses, not watery), 2 tablespoons of your favorite Bourbon whiskey, 1 tablespoon orange juice
- Reduce. Reduce the heat to low. Stir the onions and liquids until combined and fully incorporated. Cook for 10 minutes, continuing to stir occasionally. The onions will be a dark brown now and getting very soft, but not mushy.
- Broth. Add ½ cup of broth. Stir to get up the brown bits of goodness. Let the onions cook in the broth for 6-7 more minutes until the liquid thickens. Do not stir. The onion mix will be more of a gravy.3 1/2 cups beef broth (dark like coffee, not like tea)
- More Broth! Add the remaining 3 cups beef broth. Stir the onion mix to get up more brown bits of goodness and heat the broth thoroughly. Remove the soup from the heat.
- Assemble. Add 1 cup of soup to each ramekin. Add 5-6 cubes of croutons per bowl. Top with ¼ cup grated mozzarella cheese and a slice of provolone.1 cup shredded mozzarella cheese, 4 slices provolone cheese (circle slices)
- Broil. Place the ramekins on a sheet pan and the pan about 5” from the broiler. Broil 2-3 minutes until the cheese is golden bubbly.
- Enjoy! Serve immediately.
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Hi Erin,
I’ve always been a little intimidated at the thought of making French onion soup, too, but decided to try this on a cool evening. Your directions were clear, and it was much easier than I thought it would be. There was a nice subtle blend of flavors. The finished product looked almost as good as in your beautiful photos!
Hi Amy,
Thank you so much for the feedback and for trying French Onion Soup with Bourbon! I’m glad it worked for you!