Prep the mushrooms. Wipe them clean with a damp paper towel and slice. Remove tough shiitake stems. Keep a small handful aside to sauté for garnish if you like.

Sweat the aromatics. In a large pot over medium heat, add the butter and olive oil. Stir in the shallots with a pinch of salt and cook until soft and translucent, about 3–4 minutes. Add garlic and thyme; cook 30 seconds until fragrant.

Brown the mushrooms. Add the sliced mushrooms and a pinch of salt. Cook, stirring occasionally, until the mushrooms release their moisture and start to brown, about 8–10 minutes. Don’t rush this—color equals flavor.

Deglaze with wine. Pour in the white wine, scraping up any browned bits on the bottom of the pot. Let it simmer for 2–3 minutes until mostly reduced. If skipping wine, add a splash of broth and a teaspoon of lemon juice later.

Thicken lightly. Sprinkle the flour over the mushrooms and stir for 1 minute. This helps the soup feel silky without being heavy.

Add the broth and bay leaf. Pour in the broth and add the bay leaf. Bring to a gentle simmer and cook for 12–15 minutes to meld flavors.

Blend to your preferred texture. Remove the bay leaf. Use an immersion blender to blend until smooth, or transfer to a blender in batches. For a bit of texture, blend only 2/3 of the soup and return it to the pot.

Finish with cream and seasoning. Stir in the cream and a pinch of nutmeg. Simmer on low for 3–4 minutes. Taste and adjust salt, pepper, and acidity. A small squeeze of lemon brightens the flavors if needed.

Optional garnish. In a small skillet, sauté the reserved mushrooms in a little butter over medium-high heat until browned. Season and scatter on top of each bowl. Add chopped parsley or chives for color.

Serve. Ladle into warm bowls. Serve with crusty bread, a simple salad, or a grilled cheese for a cozy meal.