My sis Theresa turned me on to this recipe http://angiesrecipes.blogspot.com/2009/01/ubi-purple-yam-two-tone-bread.html Ubi, served as a potato dish as well as an ingredient, is the Filipino word for purple yam. Its flesh is a marbled violet color and is well-known for its aroma. Tangzhong starter / Water roux starter is a mixture of flour and water. NOT a sourdough starter. It keeps bread moist, soft and fluffier for a longer time period. The KEY to this starter is the temperature of the water used. The water and flour is mixed together than cooked at a 65 C/149 F temperature, the gluten within the flour absorbs all the water and become leavened. When this mixture is cooled and added to the remainder of the dough, the moisture is retained in the dough and heighten. Remove from heat and cover loosely with plastic wrap to prevent from drying. Store the starter in the refrigerator after after completely cooling down. To use the starter, measure out the amount called for in a recipe and let it warm to room temperature. Unlike sourdough starter, this special Tangzhong starter doesn't improve its flavour with age. So it's preferably to use up in 3 days. If it turns gray it went bad, discard it. Best to measure on a scale using the metric weights. If dough is wet do adjust with a touch of flour or dry with water. Take note the salt and yeast are 1/2 teaspoon each but grams are different.