Combine the yeast, one tablespoon of the sugar, the milk and the water in a bowl and let it proof for 10 minutes.

In a large bowl, combine the cornmeal, the butter, the eggs, the rest of the sugar and the salt. Add the milk/water/yeast mixture and mix with a wooden spoon. Add the flour 1 cup at a time until you form a dough and then add the sweet potato, mixing to combine.

Knead the dough for 1 or 2 minutes on a floured counter. The dough is supposed to be sticky.

Form a ball with the dough and place it in an oiled bowl, making sure you brush the dough with some oil as well. Cover it and let it rest for 1 hour or until it is double the original size.

Punch down the dough and make 18 golf sized balls. Place them in a baking pan, leaving some space in between them, and let them sit (covered) for 1 more hour or until they've doubled in size.

Brush the rolls with egg wash and bake your rolls in a 375 degrees preheated oven for about 30 minutes or until the top is golden brown.

Serve warm or at room temperature.