03Roll out the dough, oil a 14-inch pizza pan and dust with cornmeal or semolina. Place the dough on the pan.
04In a medium bowl, combine the ricotta, egg yolk, Parmesan and chard. Spread over the pizza dough in an even layer, leaving a 1-inch border around the rim. Spread the onions over the ricotta mixture.
05Place in the hot oven, and bake 10 to 15 minutes until the crust and bits of the onion are nicely browned. Remove from the heat, and serve hot or warm.