Cheese & Marmite straws

Line 2 large baking trays with baking parchment. Flour a work surface and unroll the pastry, with a short edge nearest you. Use a palette knife to spread the Marmite over the top ½, then scatter all the Gruyère and ½ of the Parmigiano Reggiano over the top. Fold the lower ½ of the pastry up and over the cheese to enclose it.

Use a rolling pin to roll out the filled pastry to a rectangle roughly 20x35cm (about 0.3cm thick). Brush with the egg yolk, then sprinkle over the remaining cheese and some cracked black pepper. Slice across the width into 2cm strips. Gently twist each strip into a spiral, then arrange on the lined baking trays. Chill for at least 10 minutes.

Preheat the oven to 200ºC, gas mark 6. Bake the straws for 15-20 minutes, until golden. Leave for 5 minutes on the trays, then transfer to a cooling rack or tuck in while still warm.