Name: Creamy French Onion and Mushroom Soup
Prep time: 10 min
Cook time: 55 min
Total time: 1 h 5 min
Cuisine: French
Ingredients: 2 tablespoons butter; 1 tablespoon olive oil; 3 large yellow onions, thinly sliced; 3 cups baby bella mushrooms, sliced; 3 garlic cloves, minced; 1 teaspoon fresh thyme leaves; 4 cups vegetable broth; 1 cup heavy cream; 1 teaspoon salt; 1/2 teaspoon black pepper

There’s something undeniably comforting about a bowl of rich, savory soup that feels like a warm hug in a bowl. Creamy French Onion and Mushroom Soup blends the deep caramelized sweetness of onions with earthy mushrooms, all swimming in a velvety broth enriched with cream and herbs. It’s a luxurious twist on the classic French onion soup that takes it to a whole new level.

Whether you’re enjoying it solo on a quiet evening or serving it as a starter at a dinner party, this soup delivers incredible flavor with minimal fuss. With simple ingredients and an elegant taste, it’s the kind of dish you’ll find yourself craving as the weather turns cool and crisp.

Why You’ll Love This Creamy French Onion and Mushroom Soup

This soup is cozy, creamy, and full of umami depth. The caramelized onions bring out their natural sweetness, which perfectly complements the savory bite of the mushrooms. It’s an affordable, vegetarian-friendly recipe that doesn’t skimp on flavor. Plus, it tastes even better the next day, making it ideal for meal prep.

What Kind of Onions Should I Use?

Yellow onions are your best bet for that signature French onion flavor. They become beautifully sweet as they caramelize and hold their texture well. You can also mix in a shallot or two for a milder aromatic boost. Avoid red onions, as they can turn bitter with long cooking times.

Ingredients for the Creamy French Onion and Mushroom Soup

The flavor of this soup comes from slow-cooked onions and a hearty helping of mushrooms. Here are the essentials you’ll need:

Yellow onions – Essential for caramelization and the rich, sweet base.

Baby bella mushrooms – Earthy and meaty, they balance the sweetness of the onions.

Garlic cloves – Add depth and savoriness to the broth.

Butter – Helps caramelize the onions and gives richness.

Olive oil – Prevents burning and balances the butter.

Fresh thyme – Brings an herby lift to the soup.

Vegetable broth – The foundation of the soup, keeps it vegetarian and flavorful.

Heavy cream – Makes the broth luxuriously creamy.

Salt and black pepper – To season and bring everything together.

How To Make the Creamy French Onion and Mushroom Soup

Step 1: Caramelize the Onions

In a large pot or Dutch oven, melt butter with olive oil over medium-low heat. Add sliced yellow onions with a pinch of salt and slowly cook for 30 to 40 minutes, stirring occasionally, until deeply golden and caramelized.

Step 2: Sauté the Mushrooms

Add the mushrooms and garlic to the pot. Sauté until the mushrooms have released their liquid and are nicely browned, about 8 to 10 minutes.

Step 3: Build the Soup Base

Pour in the vegetable broth and add thyme. Scrape up any browned bits from the bottom of the pot. Bring to a simmer and let everything cook together for 10 to 15 minutes.

Step 4: Make It Creamy

Lower the heat and stir in the heavy cream. Simmer gently for 5 more minutes, then taste and adjust salt and pepper as needed.

Step 5: Serve

Ladle into bowls and garnish with extra thyme or a swirl of cream if desired. You can also top with crusty bread and melted gruyère for a more traditional touch.

How to Serve and Store This Soup

This soup is hearty enough to serve as a main course, especially with a slice of sourdough or baguette on the side. It feeds about 4 to 6 people, depending on portion sizes. For storing, let the soup cool completely before transferring to an airtight container. It keeps well in the fridge for up to 4 days and can be frozen for up to 2 months. Reheat gently on the stove over medium heat to maintain its creamy texture.

What to Serve With Creamy French Onion and Mushroom Soup?

Crusty Bread

A slice of toasted sourdough or a warm baguette is perfect for dipping into the velvety broth.

Simple Green Salad

Balance the richness with a fresh salad dressed in lemon vinaigrette.

Herby Chicken Meatballs

Add some protein by serving alongside these Herby Chicken Meatballs.

Roasted Asparagus

The bright, roasted flavor is a great pairing with the creamy soup.

Garlic Parmesan Croutons

Toss homemade croutons on top for added crunch and flavor.

Butter Pecan Pound Cake

For dessert, follow the savory with a slice of this Butter Pecan Pound Cake.

Grilled Cheese Sandwich

Go classic and comforting with a melty grilled cheese on the side.

Caprese Salad

Add a summery twist with this Classic Caprese Salad.

Want More Soup Ideas?

If you enjoy this cozy and creamy dish, you’ll want to try these comforting soup favorites too:

Creamy Parmesan Italian Sausage Soup for a hearty, savory spoonful.
Vegan Creamy Mushroom Ramen with plant-based goodness and bold umami.
Creamy Smothered Chicken with Spinach, Potatoes, and Mushrooms if you’re craving a more filling twist.
French Onion Ground Beef and Rice Casserole for a one-pan wonder with the same familiar flavors.
Crab and Shrimp Seafood Bisque if you’re in the mood for an elegant seafood version.

Save This Recipe For Later

📌 Save this recipe to your Pinterest board so you can cozy up with it anytime.

And I’d love to know how yours turned out. Did you add cheese? Go vegan with coconut cream? Try it with leeks instead of onions?

Drop your tips in the comments—I’m always inspired by how creative this community gets.

Explore beautifully curated health-boosting soups and more comfort meals on Janet Dishes on Pinterest and find your new weeknight favorite.