Velvety Umami Mushroom Bisque with Thyme & Brown Butter

🌍 Cuisine: French-Inspired
🏷️ Category: Appetizer
⏱️ Prep: 15 minutes
🍳 Cook: 35 minutes
👥 Serves: 4-6 servings

📝 About This Recipe

This luxurious bisque is a masterclass in depth and texture, proving that keto-friendly dining can be incredibly indulgent. We utilize a blend of earthy Cremini and robust Shiitake mushrooms, slow-sautéed to unlock their deep umami potential without the need for flour-based thickeners. Finished with a swirl of heavy cream and a touch of dry sherry, this soup offers a sophisticated, silky mouthfeel that warms the soul and satisfies the palate.

🥗 Ingredients

The Mushroom Base

  • 16 ounces Cremini (Baby Bella) Mushrooms (cleaned and thinly sliced)
  • 4 ounces Shiitake Mushrooms (stems removed, caps sliced)
  • 1/4 cup Dried Porcini Mushrooms (rehydrated in 1/2 cup hot water, liquid reserved)

Aromatics & Liquids

  • 4 tablespoons Unsalted Grass-Fed Butter (divided)
  • 2 large Shallots (finely minced)
  • 3 cloves Garlic (minced)
  • 1 tablespoon Fresh Thyme (leaves only, chopped)
  • 2 tablespoons Dry Sherry (optional, for deglazing)
  • 4 cups Beef or Mushroom Broth (low-sodium)
  • 1 cup Heavy Whipping Cream (at room temperature)

Seasoning & Garnish

  • 1 teaspoon Sea Salt (plus more to taste)
  • 1/2 teaspoon Black Pepper (freshly cracked)
  • 1/4 teaspoon Xanthan Gum (optional, for extra thickness)
  • 2 tablespoons Fresh Chives (finely snipped for garnish)
  • 1 teaspoon Truffle Oil (optional drizzle)

👨‍🍳 Instructions

  1. 1

    Start by rehydrating the dried porcini in 1/2 cup of boiling water for 10 minutes. Once soft, chop them finely and strain the soaking liquid through a coffee filter to remove grit; reserve the liquid.

  2. 2

    In a large Dutch oven or heavy-bottomed pot, melt 2 tablespoons of butter over medium-high heat until it begins to foam.

  3. 3

    Add the sliced cremini and shiitake mushrooms. Sauté undisturbed for 4-5 minutes to allow them to brown and develop a deep crust before stirring.

  4. 4

    Continue cooking the mushrooms for another 5-7 minutes until they have released their moisture and shrunk significantly. Remove about 1/2 cup of the prettiest slices and set aside for garnish.

  5. 5

    Reduce heat to medium and add the remaining 2 tablespoons of butter along with the minced shallots. Cook for 3 minutes until translucent.

  6. 6

    Stir in the garlic, chopped rehydrated porcini, and fresh thyme. Cook for 60 seconds until the garlic is fragrant but not browned.

  7. 7

    Pour in the dry sherry to deglaze the pan, scraping up all the brown bits (fond) from the bottom with a wooden spoon. Let the liquid reduce by half.

  8. 8

    Add the broth and the reserved porcini soaking liquid. Bring the mixture to a gentle boil, then reduce heat to low and simmer, uncovered, for 15 minutes to meld the flavors.

  9. 9

    Using an immersion blender, purée the soup until completely smooth. For an ultra-silky texture, you can transfer it to a high-speed blender in batches.

  10. 10

    Return the puréed soup to the pot over low heat. Whisk in the heavy cream and season with salt and pepper.

  11. 11

    If you prefer a thicker bisque, sprinkle the xanthan gum over the surface and whisk vigorously for 1-2 minutes until thickened.

  12. 12

    Taste and adjust seasoning. If the soup is too thick, add a splash more broth; if too thin, simmer for 5 more minutes.

  13. 13

    Ladle the hot bisque into warmed bowls. Top with the reserved sautéed mushroom slices, a sprinkle of chives, and an optional drizzle of truffle oil.

💡 Chef's Tips

Don't wash your mushrooms under running water; wipe them with a damp paper towel to prevent them from becoming soggy. Achieving a deep brown color on the mushrooms in Step 3 is the secret to a rich, dark bisque color and intense flavor. If using a standard blender, never fill it more than halfway with hot liquid and keep the lid slightly vented to prevent pressure build-up. To make this dairy-free and still keto, swap the butter for olive oil and the heavy cream for full-fat canned coconut milk. Always use fresh thyme; dried thyme can become gritty in a smooth puréed soup.

🍽️ Serving Suggestions

Serve with keto-friendly almond flour crackers or toasted low-carb bread. Pairs beautifully with a crisp, dry white wine like a Pinot Grigio or a light Sauvignon Blanc. Serve as a starter for a main course of roasted chicken or pan-seared steak. A side salad of arugula with lemon vinaigrette provides a bright contrast to the rich soup. Garnish with a dollop of crème fraîche for an extra touch of elegance.