1) Cook the chorizo in a medium-size frying-pan over medium heat. Drain on paper towels.
2) Preheat the oven to 190°C.
3) Put the dough out onto a well-floured surface. Divide the dough into four equal pieces. Roll into 10cm circles, using a rolling pin or stretching it into circles by hand. Arrange the circles on two baking sheets lightly brushed with oil.
4) Top each pizza with tomato slices and crumbled cooked chorizo. Top with shredded cheese and sprinkle with dried oregano.
5) Bake until the dough is golden brown and cheese is bubbly, about 20 minutes. Notes: Alternatively, to make your own basic pizza dough, see this basic pizza dough recipe from Paula Deen.