Place the puff pastry sheet on a clean chopping board and slice it in half to make two squares. Then slice each of the squares in half as well. Then slice the pastry rectangles in half making triangles. You should end up with 8 pastry triangles.

Slice the cooked ham slice into smaller bits that will fit on top of the puff pastry triangles. Place a piece of ham on the wide side of the puff pastry triangle.

Slice the cheese slice into smaller bits as well, about the side of the ham. Then place a piece of cheese on the cooked ham. Season with a pinch of pepper.

Roll the crescents up carefully and place then on baking tray lined with parchment paper.

Brush with the beaten egg yolk and then sprinkle with some poppy seeds.

Bake them in a preheated oven at 375°F (190°C) for 15 to 20 minutes or until golden brown on top. Then remove crescents from the hot oven and let them cool down a little. Serve with ketchup.