I have made this bread for Thanksgiving and Christmas for many years to share at our family gatherings. Everyone loves it. It takes time as it has three risings, but it is worth it when you hear the oohhhs and ahhhhs.
Dissolve yeast in warm water. Stir in molasses, salt, shortening, caraway seed and rye flour. Beat until smooth. Mix in enough white flour to make dough easy to handle.
Turn dough onto lightly floured board. Cover; let rest 10 to 15 minutes. Knead until smooth, about 5 minutes. Place in greased bowl; turn greased side up. Cover; let rise in warm place until double, about 1 hour. Punch down dough; round up, cover and let rise again until double, about 40 minutes.
Grease baking sheet; sprinkle with cornmeal. Punch down dough; divide in half. Shape each half into round, slightly flat loaf. Place loaves in opposite corners of baking sheet. Cover; let rise 1 hour.