Purple onion soup is a wonderfully savory, subtly sweet dish that takes a classic French-inspired recipe and adds a unique twist with purple onions. If you’re tired of the same old, bland onion soups and want to try something new that’s still comforting, this is your go-to recipe. The purple onion adds a delightful color contrast and a slightly milder, more complex flavor than the typical yellow or white onions, making this soup both a feast for the eyes and the taste buds.
There’s something so inviting about a bowl of warm soup, especially when it’s a soup that delivers on both taste and nutrition. This purple onion soup is packed with rich flavors, thanks to the caramelization of the onions, and it’s super simple to prepare. Whether you’re a seasoned chef or a beginner, you’ll find this recipe easy to follow. So grab your apron and let’s dive into this culinary delight that will have your family asking for seconds!
Purple Onion Soup Recipe
Purple onion soup can be as complex or as simple as you want to make it. But at its core, it’s a comforting, slightly sweet and savory dish that’s perfect for cozy nights. The natural sugars in purple onions lend themselves to a deep caramelized flavor, and when combined with broth, fresh herbs, and a bit of cheese, the soup becomes an unforgettable dish.
Prep time: 15 minutes
Cook time: 40 minutes
Servings: 4
Ingredients Needed
Here’s what you’ll need to make the soup:
- 4 large purple onions (or red onions, if preferred)
- 2 tablespoons butter (unsalted is best for better control over the salt levels)
- 1 tablespoon olive oil (for a touch of smooth richness)
- 4 cups vegetable or chicken broth (homemade broth adds depth of flavor, but store-bought works too)
- 2 teaspoons sugar (to enhance the caramelization process)
- 2 cloves garlic (finely minced)
- 1 teaspoon dried thyme (or fresh thyme if available)
- 1 bay leaf
- Salt and pepper (to taste)
- 1/2 cup dry white wine (optional but recommended for a more refined flavor)
- 1 baguette or crusty bread (for the classic French onion soup crouton topping)
- 1 1/2 cups grated Gruyère or Swiss cheese (the cheese that melts beautifully and adds richness)
Cooking Instructions
Prepare The Onions
Start by peeling and thinly slicing your purple onions. The thinner the slices, the more uniform your soup will be, and they’ll caramelize more evenly.
Caramelize The Onions
In a large pot or Dutch oven, heat the butter and olive oil over medium heat. Once the butter has melted, add the sliced onions and a pinch of salt. Stir them occasionally to coat them evenly. Cook the onions slowly over medium-low heat, stirring often for about 25-30 minutes until they are deeply caramelized and golden brown. Don’t rush this step-patience is key to developing the deep, rich flavor that makes this soup so special.
Add Garlic And Sugar
When the onions have caramelized, add the minced garlic and cook for another 2 minutes until fragrant. Sprinkle the sugar over the onions, stirring to coat. This will help draw out the natural sugars of the onions and enhance their sweetness.
Deglaze With Wine (optional)
If you’re using white wine, pour it in now to deglaze the pot. Stir to lift any caramelized bits from the bottom of the pot, which will add even more depth to the flavor. Let the wine reduce for a few minutes until it’s mostly evaporated.
Add Broth, Thyme, And Bay Leaf
Now, pour in the broth and add the dried thyme and bay leaf. Bring the mixture to a simmer and let it cook for 10-15 minutes, allowing the flavors to meld together.
Season To Taste
Taste the soup and adjust the seasoning with salt and pepper. You can also add a bit more sugar if you want extra sweetness from the onions.
Prepare The Croutons
While the soup simmers, slice the baguette into thick pieces. Toast the bread slices in a toaster or under a broiler until they’re crispy and golden brown. Once done, set them aside.
Assemble The Soup
Once the soup is ready, ladle it into oven-safe bowls. Place a slice of toasted bread on top of each bowl of soup, then sprinkle a generous amount of cheese over the bread.
Broil To Melt The Cheese
Preheat your broiler. Place the bowls under the broiler for about 3-5 minutes, or until the cheese is bubbly and golden brown. Keep a close eye on it so it doesn’t burn!
Serve And Enjoy
Serve immediately with a sprinkle of fresh thyme or extra black pepper if desired. Pair with a crisp salad or a glass of your favorite wine, and enjoy this delightful dish!
Ingredient Insights
- Purple onions: The star of the show! Purple onions are milder and sweeter than yellow onions. They bring a pop of color and a slightly more refined flavor, making them perfect for soups where the onion flavor is a focal point. They also retain a bit of their bite even after caramelization, which can add texture to your soup.
- Butter and olive oil: Combining butter and olive oil ensures you get the richness of butter without it burning, while the olive oil adds a smoothness and a hint of Mediterranean flavor. It’s the ideal balance for cooking the onions to perfection.
- Broth: You can go with either vegetable or chicken broth, depending on your preference. Homemade broth can really elevate the flavor of the soup, but store-bought can work just as well if you’re in a pinch.
- Gruyère or Swiss cheese: These cheeses are perfect for French onion soups because they melt beautifully, creating that gooey, golden layer of cheese you can’t get enough of. Gruyère, in particular, has a nutty and slightly sweet flavor that complements the sweetness of the onions.
Expert Tips
- Don’t rush the caramelization: The caramelization process takes time, and the key to a rich onion flavor is in the slow cooking. If you try to speed it up, you’ll end up with a burnt taste instead of the sweet, savory depth you’re aiming for.
- Add a splash of balsamic vinegar: If you want to add a bit more depth and tang to your soup, a splash of balsamic vinegar towards the end of cooking can enhance the sweetness and acidity.
- Make ahead: This soup actually tastes even better the next day as the flavors continue to develop. Make a large batch and store it in the fridge for up to 3 days. Reheat on the stove and top with freshly made croutons and cheese.
- Use a non-stick pot: A non-stick pot can make the caramelizing process easier because it reduces the chances of your onions sticking and burning.
Recipe Variations
- Vegan Version: Swap the butter for vegan butter or olive oil and use vegetable broth. Skip the cheese or use a plant-based cheese alternative.
- Spicy Kick: For those who love a little heat, try adding a pinch of red pepper flakes or a chopped jalapeño to the onions while they’re caramelizing.
- Herb Variations: While thyme and bay leaf are classic choices, you can experiment with other herbs like rosemary, oregano, or sage for a twist on the traditional flavor profile.
- Cheese Variations: Gruyère is a classic choice, but you can also try mozzarella for a more melty texture or cheddar for a sharper flavor.
- Additions: Some like to add a handful of cooked bacon or pancetta for extra richness and smokiness. You could also toss in a few mushrooms for an earthy flavor.
Final Words
Purple onion soup is a dish that brings comfort and sophistication to your kitchen in equal measure. The combination of sweet caramelized onions, rich broth, and cheesy, crusty toppings is sure to warm your heart, no matter the weather outside. Plus, the vibrant color of purple onions adds a special touch that’ll have everyone at the table talking. Whether you’re enjoying it on a chilly evening or serving it at a dinner party, it’s a recipe that guarantees satisfaction.
FAQs
What Is Purple Onion Soup?
Purple onion soup is a variation of traditional French onion soup that uses purple onions (also known as red onions) as the main ingredient. The soup is characterized by its rich, savory flavor, often complemented by a sweet undertone due to the natural sugars in purple onions.
What Are The Main Ingredients In Purple Onion Soup?
The main ingredients for purple onion soup include purple onions, vegetable or beef broth, garlic, butter, olive oil, herbs like thyme and bay leaves, and seasoning like salt and pepper. Some variations may include a splash of wine or a slice of toasted bread topped with cheese for serving.
Can I Use Yellow Onions Instead Of Purple Onions In This Recipe?
While yellow onions are the traditional choice for French onion soup, you can use them in place of purple onions. However, purple onions offer a slightly milder, sweeter flavor compared to yellow onions, so the soup’s taste will differ slightly.
How Do I Make Purple Onion Soup More Flavorful?
To enhance the flavor, you can caramelize the purple onions for a longer period, allowing the natural sugars to develop and add richness to the soup. Additionally, adding a splash of wine (red or white) or a touch of balsamic vinegar can deepen the flavor profile.
Can I Make Purple Onion Soup Vegan?
Yes, purple onion soup can easily be made vegan by using vegetable broth instead of beef broth, and substituting the butter with olive oil or a plant-based butter alternative. You can also omit cheese or use a vegan cheese alternative if you prefer.
How Long Does It Take To Make Purple Onion Soup?
The total time for making purple onion soup can range from 45 minutes to 1.5 hours, depending on how long you caramelize the onions. Caramelizing onions for a deep, rich flavor typically takes around 30-40 minutes, while the soup itself will simmer for another 15-30 minutes.
Can I Store Leftover Purple Onion Soup?
Yes, leftover purple onion soup can be stored in an airtight container in the refrigerator for up to 3 days. To reheat, simply warm it on the stove over medium heat or in the microwave. The flavors may even improve as they meld together after a day or two.
What Type Of Bread Should I Use For Serving Purple Onion Soup?
Traditionally, French baguette slices are used, toasted and topped with melted cheese like Gruyère or Swiss. You can also use rustic sourdough or any crusty bread that will hold up well when toasted and submerged in the soup.
What Wine Pairs Best With Purple Onion Soup?
A dry white wine like Sauvignon Blanc or Chardonnay pairs well with purple onion soup, as the acidity balances the richness of the broth. If you prefer red wine, a light-bodied red like Pinot Noir can complement the soup without overpowering its delicate flavors.
Can I Freeze Purple Onion Soup?
Yes, purple onion soup can be frozen. Allow the soup to cool completely, then store it in a freezer-safe container for up to 3 months. When ready to eat, thaw it overnight in the refrigerator and reheat on the stove.