Preheat your oven to 180 degrees. Line a rectangular baking tray with baking paper. Remove your croissants from the packaging and add to the baking tray then into the oven for 4-6 minutes or until golden and crisp.
Meanwhile, mix mustard and honey together in a small bowl then set aside for later.
Remove the croissants from the oven and cut them in half through the centre. Spread bases with cranberry sauce. Trim ham to fit and layer onto sauce with brie. Season with pepper. Brush mustard glaze over the tops of the croissants and sprinkle with poppy seeds. Return to oven for 5 minutes to heat through. Serve.