Step 1

Heat oven to 400 degrees. Line a sheet tray with parchment.

Step 2

In a 12-inch skillet over medium-high heat, add 2 tablespoons butter and 2 tablespoons olive oil. Once hot and butter is melted, add half of the mushrooms and saute until browned, about 5 minutes. Season with salt and pepper and toss in half of the shallots, garlic and thyme. Saute until fragrant, about 2 minutes longer. Remove to a bowl.

Step 3

Repeat with second batch of mushrooms, shallots and garlic. Remove to the same bowl. After the second batch of mushrooms is cooked, add the kale and saute until softened. Add the white wine and reduce until dry, about 5 minutes. Add mushrooms back to the pan and toss everything together. Cool completely.

Step 4

Sprinkle a work surface with flour. Open the puff pastry, and use a rolling pin to roll out pastry to 18 x 13 inches (roughly the same size as a half sheet tray). Move puff pastry to the sheet tray.

Step 5

Add the mushroom filling to one side of the puff pastry. Top with Brie slices. Brush edges with egg wash. Fold the puff pastry over the filling, as if closing a book. Use a fork to seal the edges. Brush the top with the egg wash. Use a knife to score the top.

Step 6

Chill for 30 minutes in the refrigerator.

Step 7

Bake for 22 to 28 minutes, until puffed and golden brown. Slice to serve.