Preheat the oven to 180°C.

Roll out your pastry onto some baking paper (I use the paper that my puff pastry comes with) and place it onto a baking tray, then place another baking tray on top of the pastry and bake for 20 minutes.

Remove the pastry from the oven and allow to cool for 2 minutes.

With a stick blender, quickly blitz 1/2 the peas, garlic, 1 tablespoon of water and a tablespoon of ricotta (the texture must still be rough).

In a small bowl mix the ricotta and egg together with some pepper and salt then add the blitz peas and give a quick mix.

Dollop the mixture over the tart base, tear up the mozzarella and place it on the tart with the remaining whole peas, season with a bit of fresh black pepper and then place it back in the oven for about 15 minutes.

Remove from the oven, add the watercress over the top with the lemon zest and serve immediately.