Use one 12-inch and one 8-inch Dutch oven with 37 briquettes.
–International Dutch Oven Society
Coat the inside bottom of the oven with nonstick cooking spray. Preheat the 12-inch Dutch oven with nine briquettes underneath and 17 on top. Prepare the hot roll mix according to package directions for basic dough, using the egg and substituting 2 tablespoons of oil for the margarine. Knead the dough, allowing it to rest as directed. Roll the dough into a 12-inch-diameter disk, cover, and let rise until doubled.
In the 8-inch Dutch oven over 11 briquettes, heat the 2 teaspoons of olive oil. Add the onions and rosemary and cook until tender.
With your fingertips, press dimples every inch or so in the dough. Top the dough evenly with the onion mix. Carefully transfer the dough to the prepared and heated 12-inch Dutch oven. Cover and bake for 15 to 20 minutes, or until golden brown. Remove from the oven and cool on a wire rack for 10 minutes. Cut into wedges and serve.