Preheat oven to 350 degrees. Bake fillet for 30 minutes. Remove and cut fillet into 4 2x2 inch pieces. Arrange slices on platter and sprinkle on rice powder and scallions. In food processor, combine sugar, garlic, chili pepper and ginger. Make it into a paste. Stir in tuong and water. Place in a small bowl. To serve, give each person a slice of beef and pass the sauce.