Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
Prepare the mushrooms.
Gently wipe mushrooms clean.
Remove stems and finely chop them.
Make the filling.
Melt butter in a skillet over medium heat.
Sauté chopped mushroom stems, shallot, and garlic for 4–5 minutes until softened.
Stir in breadcrumbs, Parmesan, parsley, thyme, salt, and pepper.
Remove from heat.
Stuff the mushrooms.
Place a cube of Brie inside each mushroom cap.
Top with the breadcrumb mixture, gently pressing it into place.
Sprinkle with toasted pecans if using.
Bake for 18–20 minutes, or until the mushrooms are tender and the Brie is melted and bubbly.
Finish.
Garnish with fresh parsley.
Drizzle lightly with hot honey for a sweet-and-spicy twist or balsamic glaze for a rich, tangy finish.