1. Set a pizza stone on the bottom of the oven. Preheat the oven to 500°. Dust a baking sheet with flour. Shape each piece of pizza dough into a disk, transfer to the baking sheet and dust with flour. Cover loosely with plastic wrap and let rise at room temperature for 25 minutes.
2. In a large skillet, heat 2 tablespoons of the olive oil. Add the onions, cover and cook over moderate heat, stirring occasionally, until lightly browned, about 10 minutes; transfer to a bowl. Add the artichoke hearts and rosemary to the skillet and heat through. Season with salt and pepper and add to the onions.
3. Heat the remaining 1 tablespoon of olive oil in the skillet. Add the spinach and cook over moderate heat, stirring, until heated through, about 2 minutes. Season with salt and pepper.
4. For each pizza, on a lightly floured surface, roll 1 disk of dough into a 9-inch round. Flour a pizza peel and slide the dough onto it. Spread one-fourth of the spinach and artichoke hearts on the dough. Top with one-fourth of the Fontina and 1 tablespoon of the pecorino. Bake on the stone for about 6 minutes, or until crisp and bubbling. Cut into wedges and serve.
Notes: One Serving 520 calories, 19.8 gm total fat, 4.7 gm saturated fat, 70 gm carb.