Mushroom Soup Recipe

Sweat onions and aromatics

In a 4-quart pot over medium heat, melt 2 tbs unsalted butter. Add the thinly sliced yellow onion and a pinch of salt. Cook, stirring occasionally, until the onions are soft, translucent and lightly golden, about 10–12 minutes. Add the minced garlic and cook 30–45 seconds until fragrant.

Cook mushrooms

Increase heat to medium-high. Add the sliced cremini and button mushrooms to the pot. Cook, stirring occasionally, until mushrooms release their liquid and it mostly evaporates and mushrooms begin to brown, about 6–8 minutes.

Make a roux

Sprinkle 2 tbs all-purpose flour over the mushrooms and onions and stir to coat. Cook the flour 1–2 minutes to remove the raw taste, stirring constantly so it doesn't burn.

Add stock and simmer

Gradually whisk in 4 cups low-sodium chicken stock, scraping up any browned bits from the bottom of the pot. Add 1 tsp fresh thyme leaves, 1 bay leaf, 1 tsp soy sauce (or tamari), 1 tsp salt, and 1 tsp freshly ground black pepper. Bring to a gentle simmer, reduce heat to low, and cook uncovered for 15 minutes to meld flavors.

Finish with cream and adjust seasoning

Remove and discard the bay leaf. Stir in 1 cup heavy cream and heat through (do not boil) for 3–4 minutes. Taste and adjust salt and pepper as needed. For a smoother texture, optionally use an immersion blender to purée half the soup for body while leaving visible mushroom slices, or purée fully for a creamy soup.

Prepare bread slices

Preheat oven to 425°F (220°C). Arrange the 12 baguette slices on a baking sheet. Brush each slice lightly on both sides with 2 tbs olive oil (or use melted butter for a richer flavor).

Top with cheese and season

Mix 2 cups shredded Monterey Jack with 1 tbs grated Parmesan, 1 tsp garlic powder, and 1 tsp dried oregano. Pile about 2–3 tbs of the cheese mixture onto each baguette slice, pressing slightly so cheese adheres.

Toast until bubbly and golden

Place the baking sheet under the broiler on high (or in the center of the oven at 425°F) for 2–4 minutes, watching closely, until the cheese is melted, bubbling and lightly browned. Remove from oven and brush edges with 1 tbs melted butter if desired. Let cool 1–2 minutes so cheese sets.

Ladle the hot mushroom soup into warmed bowls (about 1 to 1 1/4 cups soup per serving). Place one or two pieces of the toasted au gratin Monterey Jack crustini on top of each bowl or serve alongside so they keep crisp.

Sprinkle each bowl with 2 tsp chopped chives and finish with a small drizzle (about 1 tsp) of extra-virgin olive oil. Serve immediately.