Adding sweet potato to the dough creates a loaf with a rich golden crust and the crumb is beautifully moist. Make sure you use the deep yellow sweet potatoes, in preference to the white variety of sweet potatoes, to give the bread a lovely colour.
Cook the sweet potato in plenty of boiling water for 40 minutes or until very tender. Drain, and when cool enough to handle, peel off the skin. Place the sweet potato in a large bowl and mash well, but do not add any butter or milk.