Stretch out the dough to fit a shallow baking tray, 25cm x 40cm. Press the dough into the edges so it fits well.
Spread the tomato paste evenly over the pizza. Sprinkle over the rosemary, sliced mushrooms and tinned tuna. Evenly distribute the chopped tomatoes, capers and chopped anchovies. Crumble over the ricotta and drizzle with olive oil.
Bake 25 minutes or until the dough is brown at the edges. Sprinkle with the basil. Let cool a little then cut into even squares.