Preheat oven to 375°F (190°C) and line a white ceramic baking dish.
Slice each chicken breast to create a deep pocket for stuffing.
Stuff each chicken breast with sautéed spinach, brie slices, and cranberries.
Season chicken with salt, pepper, and thyme, then sear in olive oil for 2–3 minutes per side.
In a small pan, melt butter with honey and balsamic vinegar until glossy.
Drizzle glaze over chicken and bake 25–30 minutes until golden and brie starts to melt out.
Spoon extra glaze over top, garnish with thyme sprigs, and serve warm.
