Combine the yeast, water and sugar in a bowl. Let sit until yeast rises, about 5 minutes. Add salt, beaten egg and evaporated milk. If using a stand mixer- mix on low speed, and add half of the flour . Put the shortening in a small bowl, microwave- just until shortening starts to melt. Add the shortening to the dough, mix well. Add remaining flour a little at a time. When flour is incorporated into the dough, and it is no longer sticky,turn dough onto a lightly floured board. Knead a few times. Place the dough into a clean oiled bowl. Cover and let raise for at least 1 hour. This dough can also raise overnight in the refrigerator.