Wild Mushroom Caramelized Onion And Kale Soup

The onions begin pale and sharp, then slowly turn soft and deeply golden while the kitchen fills with a sweet, savory smell. That long, gentle start is what gives this wild mushroom caramelized onion and kale soup its rounded flavor instead of a pot that tastes like broth with vegetables floating in it.

I brown the mushrooms separately, in batches, so they have room to color rather than steam. The potato adds a little body as it simmers, but the soup stays brothy and full of texture. Kale goes in near the end, and a touch of lemon keeps the cream from making each spoonful feel heavy.

Give the onions their time, and this is a satisfying, earthy soup with tender greens, browned mushrooms, and a bright finish.

Why the Mushrooms Need Room to Brown

Mushrooms hold plenty of moisture. Put all of them into the pot at once and the temperature drops; instead of browning, they release liquid and soften in their own steam. That still cooks them, but you lose the deep, savory edges that make this soup taste like it has been simmering much longer.

Cooking the mushrooms in three batches gives each piece more contact with the hot pot. Let them cook for several minutes before stirring, then move them aside once they’re browned. The first batch can wait on the plate while the next one cooks; it will return to the pot with the onions and broth.

Those browned bits left behind are worth keeping, too. The garlic and thyme cook briefly in the same pot, and the dry sherry loosens the fond when you scrape the bottom. That savory layer becomes part of the broth rather than staying stuck to the cookware.

What Gives This Soup Its Earthy Flavor and Gentle Body

• Mixed wild mushrooms — Shiitake, oyster, and maitake are all good choices, and using more than one gives you a mix of meaty and delicate bites. Fresh mushrooms should feel firm, not slick; trim away tough stem ends before slicing. A single variety works too, though the bowl will have a more uniform mushroom flavor.
• Yellow onions — Their sweetness deepens as they soften and caramelize, balancing the mushrooms’ earthy flavor. Slice them thinly and evenly so they cook at a similar pace. Yellow onions are the right everyday choice here; the long cooking does more for their flavor than seeking out a specialty onion.
• Dry sherry — A dry, not sweet, sherry lifts the browned bits from the pot and adds a nutty note to the broth. Use one you’d be happy to drink; a sweet sherry would push the soup in a sugary direction. If sherry isn’t available, the FAQs explain how to deglaze with broth instead.
• Yukon Gold potato — This variety becomes tender while keeping its pieces intact, and it lends the broth a little more substance without turning the soup into a puree. Peel it if you prefer, but cut it into even cubes either way so it cooks consistently.
• Kale — Remove the firm stems before chopping; they take longer to soften than the leaves. Curly and lacinato kale both work, with lacinato giving you softer, narrower ribbons and curly kale holding a little more texture.
• Heavy cream and lemon juice — Cream rounds out the broth, while lemon juice brings back some brightness at the end. Fresh lemon juice has a cleaner, livelier taste than bottled juice, and adding both only after the kale is tender keeps their flavor distinct.
• Low-sodium vegetable broth — Low-sodium broth leaves room for the salt added to the onions and soup without making the finished pot taste too salty. A good-tasting packaged broth is fine; the mushrooms, browned onions, and sherry build plenty of character around it.

Build the Soup in Layers, Then Finish It Gently

Take the Onions to Deep Gold

Heat the olive oil and butter in a 6-quart Dutch oven over medium heat, then add the thinly sliced onions and half the salt. Stir frequently as they soften, lowering the heat to medium-low as they begin to collapse. Give them 35 to 45 minutes to become deeply golden and caramelized; if the pot starts to darken too quickly, the heat is too high. Transfer the onions to a plate when they’re ready.

Brown the Mushrooms in Batches

Add the remaining olive oil to the pot and brown the mushrooms in three batches, cooking each batch for 5 to 7 minutes and stirring occasionally. The mushrooms should look browned rather than pale and wet before you move them to the plate. Crowding the pot makes them steam, so keep each batch modest even if it feels slower. Once all the mushrooms are browned, leave the flavorful residue in the pot.

Deglaze and Simmer the Potato

Add the garlic and dried thyme, stirring constantly for 30 seconds so the garlic turns fragrant without burning. Pour in the dry sherry and scrape up the browned bits, then let it simmer for 2 minutes. Return the onions and mushrooms, then add the broth, diced potato, bay leaf, remaining salt, and pepper. Bring the soup to a boil, lower the heat, and simmer uncovered for 15 to 20 minutes, until a fork slips easily into the potato.

Soften the Kale and Add the Finish

Stir in the chopped kale and simmer for 5 to 7 minutes, until the leaves are tender but still visible in the broth. Stir in the heavy cream and lemon juice, then remove the bay leaf. Warm the soup gently for 1 to 2 minutes without letting it boil; a boil can make the creamy finish less smooth. Taste a spoonful before serving so you can judge the balance of earthy, rich, and bright flavors.

Simple Changes for a Different Bowl

Questions That Come Up While Making This Soup

Wild Mushroom Caramelized Onion And Kale Soup

Wild mushroom soup gets deep flavor from slowly caramelized onions, browned wild mushrooms, and dry sherry. Kale, potato, and a little cream make this Dutch oven soup hearty and silky.

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Prep Time 20 minutes mins

Cook Time 1 hour hr 26 minutes mins

Total Time 1 hour hr 46 minutes mins

Servings: 6 servings

Course: Dinner

Cuisine: American

Calories: 280

Ingredients Equipment Method Notes

Ingredients

  

• 3 tbsp olive oil divided
• 2 tbsp unsalted butter
• 2 yellow onions large, thinly sliced
• 1 tsp kosher salt divided
• 1.5 lb mixed wild mushrooms such as shiitake, oyster, and maitake; trimmed and sliced
• 3 cloves garlic minced
• 1 tsp dried thyme
• 0.5 cup dry sherry
• 6 cups low-sodium vegetable broth
• 1 Yukon Gold potato medium, about 8 ounces, diced 1/2 inch
• 1 bay leaf
• 0.5 tsp black pepper freshly ground
• 1 bunch kale about 8 ounces, stemmed and chopped
• 0.5 cup heavy cream
• 1 tbsp lemon juice

Equipment

• 1 6-quart Dutch oven

Method

 

1. In a 6-quart Dutch oven over medium heat, heat 2 tablespoons of the olive oil and the butter.
2. Add the onions and 1/2 teaspoon of the salt; cook, stirring frequently and reducing the heat to medium-low as they soften, for 35 to 45 minutes, until deeply golden and caramelized.
3. Transfer the onions to a plate and add the remaining 1 tablespoon olive oil to the pot.
4. Brown the mushrooms in 3 batches, cooking each batch for 5 to 7 minutes and stirring occasionally; transfer each batch to the plate.
5. Add the garlic and thyme to the pot and cook for 30 seconds, stirring constantly.
6. Pour in the sherry, scrape up the browned bits, and simmer for 2 minutes.
7. Return the onions and mushrooms to the pot and add the broth, potato, bay leaf, remaining 1/2 teaspoon salt, and pepper.
8. Bring to a boil, then reduce the heat and simmer uncovered for 15 to 20 minutes, until the potato is tender when pierced with a fork.
9. Stir in the kale and simmer for 5 to 7 minutes, until tender.
10. Stir in the cream and lemon juice, remove the bay leaf, and warm gently for 1 to 2 minutes without boiling.

Notes

For the deepest flavor, let the onions cook until deeply golden and caramelized. Refrigerate leftovers for up to 4 days; freezing is possible, though the cream may separate slightly when reheated. For a dairy-free swap, use full-fat coconut cream in place of the heavy cream.