Preheat your oven to 375°F (190°C) and line a large baking sheet with parchment paper.
Using a sharp serrated knife, cut the sourdough loaf in a cross-hatch pattern (about 1-inch or 2.5 cm squares). Slice deep into the bread but be careful not to cut all the way through the bottom crust, keeping the loaf intact.
Gently pry open the cuts of the bread with your fingers. Evenly stuff the crevices with the shredded chicken, brie cheese cubes, and cranberries, ensuring they are distributed deep into the loaf.
In a small microwave-safe bowl, whisk together the melted butter, honey, chopped fresh thyme, and a pinch of salt until well combined.
Using a pastry brush, generously coat the top of the stuffed loaf with the honey butter mixture, dabbing it into the cracks so it soaks into the crumb.
Wrap the entire loaf loosely in aluminum foil to prevent the top from burning. Bake in the preheated oven for 20 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the bread is golden and crispy, and the brie is fully melted and bubbly.
Let the loaf cool for 5 minutes before serving warm. Encourage guests to pull apart the cheesy, chicken-stuffed chunks.