Follow the package directions. Instead of warm water, use tepid (room temperature) water. Add 1/4 cup dry minced onions and the melted butter. Add more flour if needed until you have a soft but not sticky dough. Knead the dough as described in the recipe directions. Place the dough in a greased bowl, cover with plastic wrap, and refrigerate overnight or up to three days.
Remove the dough from the refrigerator on the day you would like to bake the rolls. Let the dough warm on the counter for three or four hours. The dough will rise and look bubbly. Sprinkle some flour on a countertop, flour your hands, and remove the dough to the countertop. Stretch and fold the dough several times to redistribute the trapped gases, place it back in a greased bowl, and cover. Let the dough rise on the countertop until doubled, about an hour.
Prepare a non-insulated baking sheet by lightly greasing it and then sprinkling it with cornmeal.
Once the dough has risen, gently flatten the dough by patting it with a flour hand until you have a rough rectangle 11/2 inches thick. Use a sharp knife to divide the dough into pieces about the size of an egg. Form the pieces into round or oval rolls by stretching the dough around the center and pinching the seams to seal. Place seam side down on the baking sheet about 11/2 inches part. Lightly dust with flour, cover the rolls and let them rise until doubled.
Place a metal pan on the bottom rack in the oven. (You will add water to this pan to create steam in the oven. Since high heat may be hard on pans, use an older pan.) Preheat the oven to 500 degrees.
Once the dough has doubled (the rolls should be very puffy) and the oven has heated, you are ready to place water in the pan in the oven. Using an oven mitt and being very careful to avert any steam, pour about two cups of very hot water into the hot pan. Quickly close the door. Immediately take a very sharp knife or razor and make a quick slits about 1/4-inch deep across the top of each roll then place the rolls in the oven. Turn the temperature down to 400 degrees and bake for 20 minutes or until the rolls are well-colored. Different size rolls will take different times to bake. Check on the rolls progress when you feel they are about done but not before 15 minutes. When done, the internal temperature of the rolls should reach 210 degrees.
Remove the rolls to a wire rack to cool. Store any leftover rolls in a paper bag, not plastic, to protect the crust.