Wipe mushrooms clean with a damp paper towel or soft brush. Trim tough stem ends. If mushrooms are large, halve or quarter them so pieces are roughly uniform in size (about 1-1.5 in pieces). Pat dry.

Season mushrooms

Place the cleaned mushrooms in a bowl. Sprinkle with 1 teaspoon of kosher salt and 1/2 teaspoon black pepper. Toss to coat evenly and let sit 5 minutes to draw out a little moisture (this helps browning).

Heat pan

Set a large skillet over medium-high heat. Add the butter and olive oil and heat until the butter foams and just begins to brown, about 1-2 minutes. The oil raises the butter’s smoke point so mushrooms can brown cleanly.

Sear mushrooms

Add mushrooms in a single layer (work in batches if needed so they’re not crowded). Let mushrooms cook undisturbed for 3-4 minutes until the undersides are golden-brown. Stir or flip and cook a further 2-3 minutes until well browned on the other sides.

Add aromatics

Reduce heat to medium. Push mushrooms to the sides of the pan and add the chopped shallot, cooking 1-2 minutes until softened. Add the minced garlic and thyme leaves and cook 30-45 seconds until fragrant, stirring with the mushrooms so nothing burns.

Deglaze

Pour in the white wine (or stock) to deglaze the pan, scraping up any browned bits from the bottom with a wooden spoon. Let the liquid bubble and reduce slightly, about 1-2 minutes.

Finish

Stir in the heavy cream, if using, and remaining 2 teaspoons kosher salt and 1/2 teaspoon black pepper. Cook 1-2 minutes until sauce thickens slightly and coats the mushrooms. Remove from heat and stir in the lemon juice and chopped parsley.

To Serve (optional)

Taste and adjust seasoning with additional salt and pepper if needed. Spoon warm mushrooms over toasted bread slices, sprinkle with grated Parmesan, or serve as a side to protein or pasta. Garnish with extra parsley or thyme sprigs.