Name: Mushroom & Caramelized Onion Soup with Cheesy Toasties Recipe
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: French-Inspired
Ingredients: 2 tablespoons olive oil; 2 tablespoons butter; 2 large yellow onions, thinly sliced; 1 teaspoon sugar; 3 cloves garlic, minced; 1 pound mushrooms (cremini, button, or mixed), sliced; 1 teaspoon fresh thyme or 1/2 teaspoon dried thyme; 1/4 cup dry white wine (optional); 4 cups vegetable or beef broth; 1 tablespoon soy sauce or tamari (for gluten-free); Salt and pepper to taste; 4 slices crusty bread (sourdough or French bread recommended); 1 cup shredded Gruyère, Swiss, or sharp cheddar cheese; Butter for spreading

Jump to Recipe·Print Recipe

If you’re looking for the ultimate comfort food, Mushroom & Caramelized Onion Soup with Cheesy Toasties is about to become your new favorite. This cozy, French-inspired classic combines deeply sweet onions, earthy mushrooms, and a rich broth, all topped off with gooey, golden cheese toasties for dunking. It’s a recipe that transforms simple ingredients into something truly magical, perfect for brisk evenings or whenever you crave a hug in a bowl.

Mushroom & Caramelized Onion Soup with Cheesy Toasties Recipe - Recipe Image

Ingredients You’ll Need

This recipe keeps things beautifully simple, relying on a handful of staples to deliver maximum flavor. Each ingredient plays a starring role, from the rich caramelized onions to the melty cheese, creating unforgettable taste and texture in every bite of Mushroom & Caramelized Onion Soup with Cheesy Toasties.

Olive oil: Adds a fruity, robust base for sautéing and helps onions caramelize without burning.
Butter: Brings richness and classic French flavor to the onions and mushrooms.
Yellow onions: The star for achieving that deep, caramelized sweetness that gives the soup its signature character.
Sugar: Speeds up caramelization and intensifies the onions’ natural sweetness.
Garlic: Lends a subtle pungency that anchors the savory notes of the soup.
Mushrooms (cremini, button, or mixed): Offer earthy depth and a meaty bite—mixing varieties gives more complexity.
Fresh thyme (or dried): Brightens the soup with a gentle herbal note that pairs beautifully with mushrooms.
Dry white wine (optional): Deglazes the pan and adds a touch of acidity and sophistication—use broth if you prefer alcohol-free.
Vegetable or beef broth: Forms the savory backbone of the soup; use a good-quality broth for best results.
Soy sauce (or tamari): Adds umami and depth; tamari keeps it gluten-free.
Salt and pepper: Essential for balancing flavors—taste as you go!
Crusty bread (like sourdough or French): The perfect sturdy base for those irresistibly melty cheesy toasties.
Shredded Gruyère, Swiss, or sharp cheddar cheese: Melts beautifully and brings a nutty, savory punch to the toasties.
Butter for spreading: Ensures perfectly crisp, golden toastie exteriors.

How to Make Mushroom & Caramelized Onion Soup with Cheesy Toasties

Step 1: Caramelize the Onions

Begin by heating olive oil and butter in a large pot over medium-low heat. Add your thinly sliced onions and sprinkle them with sugar. Let them cook slowly for 20 to 25 minutes, stirring occasionally. You want them deeply golden and soft, with all their natural sweetness coaxed out. This is the first secret to an unforgettable Mushroom & Caramelized Onion Soup with Cheesy Toasties—patience is key!

Step 2: Sauté the Mushrooms and Garlic

Once the onions are gorgeously caramelized, add your minced garlic, sliced mushrooms, and thyme. Turn the heat up to medium and cook for 8 to 10 minutes. The mushrooms should brown and release their moisture, creating a wonderful, fragrant base. Let everything concentrate down until most of the liquid has evaporated and the flavors are rich and earthy.

Step 3: Deglaze with White Wine

If you’re using white wine, pour it in now to deglaze the pot. Scrape up all those delicious browned bits from the bottom—this is pure flavor gold! Let the wine bubble away for about 2 minutes, mellowing out and infusing the onions and mushrooms with a light acidity. If you’re skipping the wine, a splash of broth works well too.

Step 4: Simmer the Soup

Add the broth and soy sauce, stirring everything together. Bring the soup to a gentle simmer, then cover the pot partially. Let it bubble away for 15 to 20 minutes so all those flavors meld beautifully. Taste and season with salt and pepper as needed—the broth should be rich and layered, with just the right amount of savoriness.

Step 5: Prepare the Cheesy Toasties

While the soup simmers, it’s time for the best part—the cheesy toasties! Preheat a skillet or griddle. Butter one side of each bread slice, then pile cheese generously onto two of the unbuttered sides. Top with the other bread slices, buttered side out, to make sandwiches. Grill them over medium heat for 3 to 4 minutes per side, until the bread is golden and the cheese melts into gooey perfection.

Step 6: Serve and Enjoy

Slice the toasties in half and serve them alongside steaming bowls of Mushroom & Caramelized Onion Soup with Cheesy Toasties. Dunk, savor, and let the world melt away—this is comfort food at its finest.

How to Serve Mushroom & Caramelized Onion Soup with Cheesy Toasties

Garnishes

Elevate each bowl by topping with fresh thyme leaves, a sprinkle of extra cheese, or a crack of black pepper. If you want to get fancy, a drizzle of good olive oil or a few crunchy croutons add lovely contrast to the soup’s velvety texture.

Side Dishes

This soup-and-toastie combo is a meal in itself, but if you’re feeding a crowd or want a little extra, try pairing with a crisp green salad tossed in a tangy vinaigrette. Roasted vegetables or a simple tomato salad work beautifully too, balancing the richness of the Mushroom & Caramelized Onion Soup with Cheesy Toasties.

Creative Ways to Present

For a dinner party twist, serve the soup in mini mugs or espresso cups with bite-sized toastie soldiers for dipping. You can also float a cheesy toastie crouton right on top of each bowl, broiling briefly to melt the cheese for a French onion soup effect.

Make Ahead and Storage

Storing Leftovers

Leftover soup can be cooled and stored in an airtight container in the refrigerator for up to 4 days. The flavors deepen overnight, making Mushroom & Caramelized Onion Soup with Cheesy Toasties even more delicious the next day!

Freezing

The soup base freezes beautifully. Let it cool completely, transfer to freezer-safe containers, and freeze for up to 2 months. Thaw overnight in the fridge before reheating. For best results, make the cheesy toasties fresh each time, as bread and cheese don’t freeze quite as well.

Reheating

Gently reheat the soup on the stovetop over low heat, stirring occasionally, until steaming hot. If the soup has thickened in the fridge, just add a splash of broth or water to loosen it up. Toasties are best reheated in a skillet or toaster oven to regain their crisp, melty glory.

FAQs

Can I use a different type Main Course, Soup

Absolutely! Any fresh mushrooms you have on hand will work—try a mix of cremini, button, shiitake, or even portobello for extra depth. The more variety, the more complex the flavor in your Mushroom & Caramelized Onion Soup with Cheesy Toasties.

Is the soup gluten-free?

The soup itself can be made gluten-free by using tamari instead of soy sauce and ensuring your broth is gluten-free. For the toasties, simply opt for your favorite gluten-free bread.

Can I make the soup vegan?

Yes! Swap the butter for more olive oil or a vegan butter, use vegetable broth, and choose a plant-based cheese for the toasties. You’ll still get all the wonderful flavors that make this Mushroom & Caramelized Onion Soup with Cheesy Toasties so comforting.

Can I blend the soup for a creamier texture?

Definitely. For a thicker, creamier bowl, blend part or all of the soup using an immersion blender or in batches in a regular blender. Stir in a splash of cream or cashew cream at the end if you like it extra luscious.

What wine pairs best with this soup and toasties?

A crisp Sauvignon Blanc or lightly oaked Chardonnay works beautifully, echoing the flavors in the soup and cutting through the richness of the cheese. For a red option, try a light Pinot Noir.

Final Thoughts

There’s something incredibly special about making Mushroom & Caramelized Onion Soup with Cheesy Toasties from scratch—the aroma, the bubbling cheese, the first luscious spoonful. If you’re in need of a little warmth and comfort, gather your ingredients and give this recipe a try. You’ll be amazed at just how satisfying a simple, homemade soup and toastie can be!

Mushroom & Caramelized Onion Soup with Cheesy Toasties Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

4.9 from 24 reviews

Author: admin
Total Time: 55 minutes
Yield: 4 servings 1x
Diet: Non-Vegetarian

Print Recipe

Description

A comforting, French-inspired mushroom and caramelized onion soup paired perfectly with crispy, cheesy toasties. This vegetarian recipe combines deeply caramelized onions, savory mushrooms, and melted Gruyère cheese for an indulgent yet wholesome meal.

Ingredients

Scale

For the Soup:

2 tablespoons olive oil
2 tablespoons butter
2 large yellow onions, thinly sliced
1 teaspoon sugar
3 cloves garlic, minced
1 pound mushrooms (cremini, button, or mixed), sliced
1 teaspoon fresh thyme or 1/2 teaspoon dried thyme
1/4 cup dry white wine (optional)
4 cups vegetable or beef broth
1 tablespoon soy sauce or tamari (for gluten-free)
Salt and pepper to taste

For the Cheesy Toasties:

4 slices crusty bread (sourdough or French bread recommended)
1 cup shredded Gruyère, Swiss, or sharp cheddar cheese
Butter for spreading

Cook Mode Prevent your screen from going dark

Instructions

Caramelize the Onions: In a large pot, heat olive oil and butter over medium-low heat. Add the thinly sliced onions and sugar, then cook slowly for 20–25 minutes, stirring occasionally, until the onions are golden and deeply caramelized, building rich sweetness.
Cook Mushrooms and Garlic: Add the minced garlic, sliced mushrooms, and thyme to the pot. Increase heat to medium and cook for 8–10 minutes, stirring frequently until the mushrooms brown and their moisture mostly evaporates, intensifying flavor.
Deglaze with Wine: Pour in the white wine, if using, to deglaze the pot. Scrape up any browned bits stuck to the bottom, and cook for 2 minutes to reduce the liquid and concentrate flavors.
Add Broth and Simmer: Stir in the vegetable or beef broth and soy sauce. Bring the mixture to a gentle simmer, partially cover with a lid, and cook for 15–20 minutes to meld all the flavors. Season with salt and pepper to taste.
Prepare Cheesy Toasties: While the soup simmers, preheat a skillet or griddle over medium heat. Butter one side of each bread slice. On the unbuttered side of two slices, evenly divide and spread the shredded cheese. Top with the remaining bread slices, buttered side out, forming sandwiches.
Grill the Toasties: Grill the sandwiches for 3–4 minutes per side until the bread is golden brown and the cheese melts into gooey perfection.
Serve: Slice the cheesy toasties. Ladle the hot mushroom and caramelized onion soup into bowls and serve alongside the toasties for dipping or eating on the side.

Notes

For a creamier soup, stir in 1/4 cup heavy cream or cashew cream just before serving.
Blend half the soup if you prefer a thicker, creamier texture.
The cheesy toasties also taste fantastic with a light spread of Dijon mustard inside for an extra tangy kick.

Prep Time: 15 minutes
Cook Time: 40 minutes
Category: Main Course, Soup
Method: Stovetop
Cuisine: French-Inspired