Begin by caramelizing the onions. Thinly slice the onions. In a wide skillet heat 2 tbsp of the butter along with the olive oil over medium heat. When the butter has melted, add the sliced onions. Sprinkle with 1 tsp of kosher salt. Continue to cook on medium for 3 to 4 minutes until the onions begin to soften.
Turn the heat to low and continue cooking until the onions are very tender and a deep brown colour. This will take 45 to 60 minutes. Stir the onions regularly to ensure even cooking and to prevent sticking to the pan.
When the onions are done transfer to a bowl and set aside.
Preheat the oven to 400° F / 204°C.
Peel and quarter the pear. Slice the pear quarters crosswise rather than lengthwise so the pieces are approximately 1 inch wide. Heat 1 tsp butter in a small skillet over medium high heat. Add the pear slices and sauté for 2 to 3 minutes until the pears soften but still hold their shape. Transfer to a bowl and set aside.
Slice the brie cheese. Cut each slice into 2 or 3 pieces about 1 inch wide.
Make five deep cuts about an inch apart in the bread. Cut three quarters of the way down but not all the way through the bread. Turn the bread and make five more deep cuts crosswise to create a chessboard pattern.
Start with the caramelized onions. Spread the onions evenly along each cut in the loaf. Insert a piece of brie cheese along the slices between each cube of bread. Follow with the pear, adding a slice beside each piece of brie.
In a small saucepan melt the remaining 4 tbsp of butter. Add the chopped fresh parsley and thyme along with a pinch of kosher salt and pepper.
Tear two long pieces of foil and cross them on a baking sheet. Place the stuffed loaf in the middle of the foil. Brush the loaf evenly with the butter mixture. Gather up the sides of the foil around the loaf to partially cover. Add another piece of foil to tent on top.
Bake for 20 to 25 minutes until the cheese is completely melted. Let cool briefly before digging in!