First make the filling. Heat 2 tablespoons of the oil in a saucepan. Add the onion and garlic and fry until the onion is soft.

Stir in the tomatoes and can juice, salt and pepper, tomato puree (paste), half the oregano and the bay leaf, and bring to the boil.

Reduce the heat to low and simmer for 30 minutes, or until the sauce is thick. Remove the bay leaf.

Preheat the oven to very hot 230°C (Gas Mark 8, 450°F).

Cut the pizza dough in half and roll out each piece into a circle about 1/2 cm (1/4 in) thick. Arrange the circles, well spaced apart, on a well greased baking sheet. Spoon the sauce over the dough and arrange the cheese slices on top. Sprinkle over the remaining oregano and arrange the pepperoni slices over the top. Dribble over the remaining olive oil.

Put the baking sheet into the oven and bake for 15 to 20 minutes, or until the dough is cooked through and the cheese has melted.

Serve at once.