Preheat the oven to 200⁰C/400⁰F/Gas Mark 6.
Make a simple pizza dough by mixing the flour, yeast, salt and sugar into a dough with the olive oil and water. Knead for 10 minutes until smooth.
Roll out the dough thinly into a circle approx. 10” in diameter. Prick the dough all over with a fork and bake in the oven for 8 minutes until just starting to brown.
Remove the base from the oven and spread the passata. Return the pizza to the oven for a further 5 minutes. Then add the mussels and bake for another 2 minutes to heat the mussels through.
Remove from the oven. Top with shavings of Parmesan and fresh rocket leaves.