Pare and quarter sweet potatoes. Trim all fat from pork; brown, a few pieces at a time, in a little of the trimmered fat in a large skillet. Remove with a slotted spoon and reserve.

Arrange potatoes around edge of slow cooker; place half of meat in middle. Top with layer each of half of the onion slices and apple rings; sprinkle with half the brown sugar. Repeat to make a second layer of meat and onion. Overlap remaining apple rings around edge, sprinkle remaining brown sugar over.

Combine apple juice, salt, marjoram and pepper in a 2 cup measure. Pour over apple rings, cover. Cook on low for 8 hours or on high for 4 hours, or until pork is tender.

Sprinkle with chopped parsley before serving.