Finely grate the courgette into a bowl. Add the minced garlic, pepper and toss well.
In another bowl, mix the harissa and tomato paste, then add the lemon juice.
Unroll the pastry onto a flat surface and cut it in half horizontally. So you should get 2 long rectangles. Coat both with the tomato & harissa paste then scatter the courgette mixture on top, spread it out evenly.
Roll up the pastry, tightly on its shorter side, to create a long sausage shape (looking like a thin swiss roll). Rest it in the fridge until you’re ready to bake.
Preheat the oven to 180C degrees.
Line 2 baking sheets with parchment paper.
Cut the pastry rolls into 1cm slices and place these on the sheets.
Bake for 10-12 minutes until golden and crispy.
Let them cool, then serve.