Preheat your oven to the highest heat possible.
Form a ball from the dough. Start by making a circular motion with the palm of your hand, with some pressure. Then release the pressure gradually until you get a nice ball shape. You need 280 g or 10 oz pizza dough for a regular pizza, and 140 g or 5 oz for a small pizza.
Put your pizza dough balls on a lightly floured work surface. Dust them with some more flour, and let them proof covered with a kitchen towel for another 15 minutes.
Shape your dough to form a large, thin disk and place it in a pizza pan.
Put your tomato purée (passata) on top of your pizza dough, in the middle. With a back of a spoon or a ladle, using circular motions towards the edges, make sure the tomato covers your pizza dough. Leave an edge about 1 inch (2-3 cm) thick.
Add your mozzarella cheese. Just tear it in bite size pieces, and place them over the tomato sauce. Drizzle a few drops of extra virgin olive oil and sprinkle some dried oregano and salt.
Cut your mushrooms and tomatoes into 1/4-1/5 inch (5-6 mm) slices. Cut your artichoke hearts into 8. Tear your ham into bite-size pieces.
Your toppings should go into each quarter of your 4 seasons pizza: one quarter for your ham, another for your mushrooms, the third for the tomato and the last quarter for the artichokes.
Transfer your four seasons pizza into the oven. Bake for 10 minutes, or until the edges are slightly browned.