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